That is amazing... before I read the link Tod posted, I thought this must have happened in California... it did. Amazing....
I got suspended once for getting caught spraying pepper spray on the toilet seats.... teacher heard me & i did not know he was there. It dries transparent for the most part (if you find the right kind) If you sit on a toilet that has pepper spray that is dried, it will start to burn REAL BAD in about 30 minutes... try it sometime. It is very funny to watch what happens... it is a delayed response.