While a tiny bit WILL turn shit purple (and it doesnt go away) it's used to remove iron from water (I believe thats correct) ... it's not sold in ALL AREAS because some places simply don't have water that warrants it.... god, I remember writing that synth many yearss ago - and if you found it then you would see I included the catalog # for it in there - you can have any sears order it - a lot of people said they can't find it locally, but I am fairly certin that Sears still carries it (in a blue and white bottle) - if not just open the phone book and start calling Home and Garden supply places, as well as water treetment places.. if it comes down to it, look under "chemical suppliers" - but if you have to go as far as looking toward a chemical supplier, don't even fuck with this route, for there is a much better way to make it (the idea behind the KMnO4 for the synth was that it was 100% OTC, required no lab equiptment or even so much as a heat source... but lets not get into drug chemistry talk - also, if you follow that recipe as it's written, you will end up with a goo that you will have to wash multiple times, even then you wont have crunchy, clear crystals ... in response to a million emails I was getting, I re-wrote it (as a .html web page and modifed it in anumber of ways (still OTC with no sopecial equiptment, just more accurate with sexy crystals after one wash) ...