This is worth the $5 all by itself.
I’ll second Max Torque’s college experience. Some of my classmates were on Rifampin following a meningitis outbreak and they said that it turned “everything, and I do mean EVERYTHING” orange.
R.e. Pepto Bismol tablets - scared the bejeebers out of me the first time I took 'em, didn’t realize that saliva, tongue and poop would all turn black. There’s a cure for the first two though, after chewing the tablets brush your teeth (and tongue and gums) thoroughly, that pretty much takes care of the public mess.