Here’s an occasionally updated potion list.
As you’ve discovered, piss liquor is indeed a thing, and it can be taken yourself or used on an npc.
As far as showing a bladder meter, it’s not a bad idea. It’s been asked for, but the urination isn’t really based on a meter, it’s more like a cooldown. There are flags, and you move progressively through the stages: “can pee” -> “must pee” -> “emergency.” There’s some randomness to it as well.
I could change it to be like a number that goes up over time instead, though, and I might, if only to get some sort of meter or bar for it in the UI. I also need to find a place for it in the UI, and if I add pee, I’ll have to add lactation too. I’ll do some mock ups or something though.