Yeah I guess I'm not trying to say NDF or whatever doesn't work. Used properly it probably works fine. But with DMSA this isn't really an opinion issue... its a synthetic chemical compound of which the forumla is known. There aren't any mercury molecules in the formula. So I don't see how there is any argument.

http://www.chemindustry.com/chemicals/767979.html

Whether it works for you or not, and whether another product does, is a different story...