Be careful with potassium permanganate. It will make a mess of anything it touches, and is very hard on skin, eyes, etc. I use the stuff at work to clean up solvent spills in groundwater. Like adeeden says, it is a very strong oxidizer and will give off plenty of heat as it reacts with water and whatever it touches. I would not use or store it near anything flammable (lacquer thinner, acetone, spray paint, etc).