Be mindful of selenium too in your NOW supplement - it's been a while since i researched the selenium/mercury connection but do recall the pubmed studies of it having an affinity with mercury and the possibility of it allowing the mercury through the BBB, having binded with the selenium.
I cannot tolerate selenium at all - whatever dose i get a splitting headache for 48hrs.
I have metal issues which i'm going to be focusing on more in the future...once detox pathways are in better shape!
Can vouch for charcoal tablets - they constipate me so bear that in mind, have something on hand to increase BM's while on it just in case.