Only slightly related. What would happen if it's used as a cock ring? I don't take Mr Frodo as someone into buttsex, but what if it happened accidentally?
It's pretty obviously cannon that any extremity put into the ring will cause thew entire person/hobbit to disappear; thus the person using it as a cock rink would disappear while the person/hobbit receiving wouldn't have any effects.
You don't want to. The One Ring has over time changed shape which is how it likes to hop off fingers by going wide. This suggests that the one ring can shrink.