Actually I read the article on Mercola's site on Shade. I hope we are discussing the same issue! : ) I did not check out the video.
I agree that mercury is probably a contributing factor in many health problems. Unfortunately it is often so hard to diagnose, takes so long to treat and at least some people are very sensitive to the chelation method.
When I was new to the topic and suspected I needed to chelate lead, I was surprised at how many people had bad reactions to one chelation method or another, including natural things.
Actually some of the worst stories I've heard have been from those using the natural chelators cilantro and lipoic acid. Some people, including a close friend, go downhill fast. I've also heard some really amazing reports from those who used frequent dose lipoic acid for a couple of years or more. I have no doubt that others have benefited from use of DMSA, DMPS, EDTA depending on the toxin they were trying to chelate.