Is rinsing with water enough? | The diary offers no safety guarantee [OK Prostate Chip]

This page is based on entries from "ok-lab's diary" (https://ok-lab.hatenablog.com/), the Japanese development diary written by Mr. Okada, founder of OK Lab, a small company in Japan (Okada Comfortable Life Laboratory). Only the entries about "cleaning with just water" are summarized here, in order of publication. Past prices and sizes are as written at the time. Current prices come from the official product list (retrieved September 4, 2026). Quotations are translated from Japanese.

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Note: This page is a personal reading log by someone with no connection to the maker or the seller. It reflects the source entries as of their publication dates and makes no guarantee of accuracy or safety. The product is not a medical device; talk to a doctor about any health decision. Check the official site for current information. This page contains advertising.

In short

Mr. Okada's early experience with water-only cleaning came with an explicit warning that it guaranteed nothing.

The maker favored additional disinfection and later called a missed disinfection after toilet contact a mistake.

Current listings include the ceramic anal chip and slide-lock accessory; the May 2026 wire design remained a personal prototype.

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About this product

The OK Prostate Chip is a small device that is placed in the urethra (the urine passage) so that it acts on the prostate; the maker sells it in several shapes, sizes and materials. It is made and sold by OK Lab (Okada Comfortable Life Laboratory), a small company in Japan, through its own online store, and prices are in Japanese yen (JPY). The maker's development diary, "ok-lab's diary", is written in Japanese. This page is an English summary of it, and every quotation is translated. OK Lab ships internationally, so readers outside Japan can order (see "Buying from outside Japan" below). Product names on this page are plain-English descriptions. The official Japanese product name is shown once in the product table so you can find the same item in the store.

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Before you read: key terms

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What happens: cleaning with just water

The OK Prostate Chip is a small device placed in the urethra (the urine passage) to act on the prostate. Water-only cleaning means washing without the alcohol or heat treatments discussed in these entries. This topic covers urethral chips, separate anal chips, and an external accessory on the penis. Mr. Okada discusses removing dirt, maintaining cleanliness, and restoring the shape of fine wire loops, with different claims for these different devices.

Cleaning with just water brought no early safety guarantee

In an entry published in October 2017, Mr. Okada described almost daily tests of various chips over nearly 1 year. He reported washing only with water and experiencing neither bladder infection nor inflammation of the prostate during that period. He explicitly said this history offered no guarantee, suggesting that his surroundings might simply have contained relatively few bacteria.

He also described personal cleaning around the urethral opening as part of his routine before testing. He stressed that he did not know what conditions other users faced and urged them to take care over hygiene. Mr. Okada considered alcohol disinfection (additional cleaning for hygiene) better than water alone and also described hot-water disinfection as effective.

(Source: ok-lab's diary, published October 2017)
https://ok-lab.hatenablog.com/entry/20171026/1508989298

Cleaning with just water was only one suspected cause of illness

In an entry published in June 2018, Mr. Okada reported sudden urethritis (inflammation of the urine passage), with his temperature reaching 39.2°C. At his medical visit, he suggested that relying on water instead of boiling or alcohol disinfection might have contributed. He also raised seasonal bacterial growth, and he reports that the doctor initially agreed this was a possible explanation.

After seeing a new chip sample, however, the doctor reportedly considered it too large and suggested strain from prolonged use could explain the illness. The diary does not record which possible cause was confirmed or what the planned follow-up visit established. Mr. Okada cautioned readers about how suddenly the illness had appeared.

(Source: ok-lab's diary, published June 2018)
https://ok-lab.hatenablog.com/entry/20180623/1529741851

Cleaning with just water applied to covered anal chips

In an entry published in October 2018, Mr. Okada discussed anal chips (devices used through the anus) with condom covers. He had considered rubber coating for resin, then preferred a separate covering because he expected rubber to make cleaning harder. According to him, the covering kept the chip entirely free of dirt and made the previously discussed bleach cleaning unnecessary.

He described the remaining residue as mainly the condom's lubricant (a slippery coating). He also reported that covered designs felt much gentler during his own tests. For those covered anal chips, Mr. Okada considered water or dishwashing detergent sufficient to remove that residue.

(Source: ok-lab's diary, published October 2018)
https://ok-lab.hatenablog.com/entry/20181020/1540018080

Cleaning with just water preceded chills after toilet contact

In an entry published in February 2022, Mr. Okada described sudden chills and what he considered a mild fever. He recalled a plain vibrating chip (Fetus chip) touching the toilet, followed by only a light rinse instead of renewed disinfection. He suspected urethritis and reported taking Flomox, an antibiotic (infection medicine), with the fever and chills almost gone by the next morning.

He reported no discomfort in the urine passage and left open the possibility that something else had caused the fever. He also considered possible injury from a different chip used earlier, leaving more than one explanation under discussion. Mr. Okada called the missed disinfection a mistake and said the cause needed investigation if the illness had been urethritis.

(Source: ok-lab's diary, published February 2022)
https://ok-lab.hatenablog.com/entry/2022/02/19/123621

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The maker's answer to cleaning with just water

Mr. Okada's later water-washing claims address visible dirt, external hygiene, and wire shape, without establishing protection against infection.

Cleaning with just water removed dirt from one ceramic anal chip

In an entry published in July 2022, Mr. Okada returned to a ceramic anal chip with two bumps and a U-turn shape. He described testing it alongside a glass-tipped urethral chip with an old rubber connection and a screw-shaped helper part. In his account, the ceramic chip pressed on the prostate from the anal side more strongly than he had expected.

His cleaning observation concerned how readily dirt came off the ceramic surface. The diary does not record whether any infection testing accompanied that observation. Mr. Okada presented water washing as sufficient for removing dirt from that ceramic anal chip and described this as convenient.

(Source: ok-lab's diary, published July 2022)
https://ok-lab.hatenablog.com/entry/2022/07/09/123142

Cleaning with just water included attention to an external accessory

In an entry published in November 2023, Mr. Okada described wearing a slide-lock gatekeeper (an accessory worn on the penis) for about 2 weeks. He said it had remained in place during bathing and had become so unobtrusive that he largely stopped noticing it. He attributed his comfort partly to a fortunate fit, following earlier adjustments to its ring size.

That account nevertheless included about 2 washes a day, covering the accessory and the penis together. The diary does not record whether this routine prevented infection or how it compared with disinfection. Mr. Okada's reported hygiene measure was regular washing of the device together with the surrounding skin.

(Source: ok-lab's diary, published November 2023)
https://ok-lab.hatenablog.com/entry/2023/11/11/122638

Cleaning with just water restored fragile prototype loops, according to Mr. Okada

In an entry published in May 2026, Mr. Okada described prototype loops made from 0.03mm nitinol wire (the prototype's wire material). He reported that mucus made the loops gather together and that water washing restored their previous shape. His observation concerned the loops' shape; the diary does not record whether washing eliminated bacteria.

He also explained that producing the fine loops was difficult enough for a small mistake to ruin the work. At publication, he said the design remained his personal prototype and he could not accept customer orders for it. Mr. Okada cautioned that tangled lint could lead to breakage when someone tried to free it from the delicate wire.

(Source: ok-lab's diary, published May 2026)
https://ok-lab.hatenablog.com/entry/2026/05/16/122906

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How cleaning with just water changed over time

The diary does not say what the current state is.

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OK Prostate Chip products related to cleaning with just water

The current list includes the plain vibrating chip, ceramic two-bump anal chip, and slide-lock gatekeeper discussed in these entries.

Products that appear in these entries

The plain vibrating chip is listed in OK Lab's own online store.

The ceramic two-bump U-turn anal chip is listed in OK Lab's own online store.

The slide-lock gatekeeper is listed in OK Lab's own online store.

(Source: ok-lab's diary, published February 2022)
https://ok-lab.hatenablog.com/entry/2022/02/19/123621

(Source: ok-lab's diary, published July 2022)
https://ok-lab.hatenablog.com/entry/2022/07/09/123142

(Source: ok-lab's diary, published November 2023)
https://ok-lab.hatenablog.com/entry/2023/11/11/122638

Products the diary mentioned as alternatives

The diary names no alternative.

Historical items include the June 2018 sample, October 2018 anal prototypes, July 2022 rubber-linked assembly, and May 2026 wire prototype. No matching product can be confirmed on the current list.

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Common worries about cleaning with just water

(The material contains no questions from readers.)

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Buying from outside Japan

OK Lab ships internationally to countries covered by Japan Post's EMS courier service. Overseas orders are paid in advance by PayPal. Each order carries a ¥400 (about $3 at ¥156 = $1, rate as of 2026-09-04) handling fee, and EMS shipping is charged on top. These terms come from OK Lab's official sales-terms page (written here as plain text, not a link: ok-lab.net/docs/law), checked on September 7, 2026; confirm them on the official store before you order, because they can change.

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Summary of this article

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Source: ok-lab's diary (Okada Comfortable Life Laboratory). The original entries are in Japanese; quotations on this page are translated. Photos and videos are on the original entries.