Some men receive makeshift penile implants while in prison, typically made from pieces of ordinary objects. The practice carries significant health risks. User MGreenMN, in the oddlyterrifying subreddit, 19 Dec 2021
TIL that DIY Penis Implants of Beads Carved from Toothbrushes, Dominoes or Chopsticks and Inserted Under the Skin are Fairly Common in Prisons. The practice originated with 18th century Yakuza.[NSFW] User Salt-Pile, in the Today I Learned (TIL) subreddit, 30 Jan 2019
TIL that Yakuza put small beads inside their penis for each year they spend in prison in Japan User LeonInJapan, in the Today I Learned (TIL) subreddit, 15 Jul 2018