gentian violet is an antiseptic, so you can get it at some drug stores. methylene blue is a stain they use to look at shit in microscopes, so you have to steal it from science class or get it from a sceince supply store. i found some methlyne blue in science class once, and it didn't seem to do shit.
oh yeah, potassium permanganate is used in fish ponds to disinfect.
brake fluid dosen't seem to do shit either, but i put a couple drops in my marker anyway.