They say Hg toxic people should chelate with ALA, DMSA, or DMPS for a while before taking EDTA. I don't think EDTA is a very effective Hg chelator. I think Cutler says EDTA mobilizes mercury but does not remove it from the body or something like that.
Right now I take ALA rounds for 3 days of every week, and 1200 mg of EDTA every day, in 3 capsules.