hmmm, I'm drawing kind of a blank myself. I guess this is the problem with reading so many fetish stories lol. Since I've seen the same premise as that several times but with different things. I remember one with a ring that did it, but that's as close to the premise your describing and I think only one person used it in the story. One place you could look though is
https://thechangingmirror.com/phpbb/ they have alot of stories people find and backup onto there from various authors. So it's worth a good look, and most people label the stories correctly.