when i was in high school i used this as a senior prank (yes i was the devil in high school, but constantine exorcised the demons out of me)... take PH indicator (preferably phenylthalene), liquid form, you know the stuff that turns colors when you add it to something to tell if its acid or base. anyways 1-5 drops of this (depends on weight and metabolism, but guess high just to make sure you get full effect) in someones coffee or soda (make sure it has a lid so they not notice slight color change) and just wait 15-30 mins. Explosive rear functions will happen and pee changes color according to their PH level...usually blue or red!!! Also this is great because you want to make sure to do this at end of his visit to your store so that way itll happen while he is in his car...