I talked to Boyd Haley a few months ago to ask him whether his product would be available again anytime soon. (It will probably be a while.)
Anyway -- Haley is a big proponent of the "glutathione is the main way to get rid of mercury" theory, so I suspect he'd say the reason the ALA works is because of increased GSH. Of course, he's invested in his theory being right just as Cutler is, though from my limited interactions with the two, Mr. Haley seems less ego-driven than Cutler, so he may be more willing to admit it if another plausible theory came to light.