A much belated Update: the cheap, easy to get form of EDTA is NOT caustic to skin. I bought some Calcium Disodium EDTA from Iherb, various companies bottle it and you get it for cheap at various big online supplement selling websites (Iherb, Vitacost, etc).
I mixed a capsule full into about a quarter cup of water, put into an enema bottle, and into the rectum it went. No burning whatsoever. No side effects at all.
I'm going to try it long term to reduce calcium deposits in my arteries. some sites selling other forms of EDTA argue that the Calcium Disodium EDTA form "won't remove calcium deposits from the body", but I've since found a case history that it does. The sellers of other forms may be just trying to sell their more expensive form.