I don't think anyone has tested it. Go get your science lab coat on dude!
If your curious though and want to experiment, Potassium Permanganate has been tested on ich for freshwater and saltwater and is believed to be effective. Some have used it as a coral dip, but I've read it can be pretty harsh as it has powerful oxidizing properties. Really bad for inverts. But hey, potassium permanganate is a really deep purple color that definitely stains your clothes, so maybe you'll get some cool colored corals.