Yeah surely you can come up with a creative way to hide a few ounces of fake piss, try wearing a long sock? Last time I was at the doctor they didn't check my feet out... Lol.

I would do this over than in the pocket, I've actually had a buddy have fake pee in his pocket and when asked to empty his pockets he said,

"Aww, ya caught me man"

and handed over his fake piss, hahahaha. don't be like this.