You can't beat zeolite for getting more heavy metals out of your system than anything else. However, if money is an object, there is one substance that is cheap and will take out a lot of the heavy metals.
I used chlorine dioxide (MMS) to get most of my heavy metals out. After I had cleared out my mercury and cadmium with it, it took a lot less zeolite to clean up the heavy metal (copper) that chlorine dioxide wouldn't take out.