I use bentonite (a liquid mix of clay), and have used it for 2-3 years. It binds to the toxins and helps flush them out of your body. I don't know about it's helpfulness with mercury (but I assume it would be good) - I used it in my candida treatment. A mix of psyllium to srub out your digestive track, an antifungal to kill the candida, the bontonite to draw out the toxins from when the yeast dies - all mixed with water.

~Tia