The Electric Toilet Seat
The title basically explains it all, you hook up 2 or 3 electrodes to a toilet seat inside of a port-o-let or some other restroom where the guys visit, place a camera in one of the top corners of the room, or port-o-let, to monitor who's going in, and when they have a seat to drop a deuce, zap them. It would probably be best to wait a while until they get somewhat comfortable enough to drop some cargo. That way, they could spring up from the shock and make a satisfying mess. Thanks you guys, you're awesome.