Bex.
It is not this simple. You said that iodine caused some mercury symptoms for you. But iodine is anti-bacterial and Dietrich Klinghardt who is some kind of a Lyme specialist recommends it against Lyme. Iodine will naturally work against other bacterias as well. There is also a problem with anti-fungals. Fluconazole has been found to be efficient against Lyme as well, even though it is an anti-fungal. DMSA has lots of other properties as well, not only being a mercury chelator. Based on this you can't even know what the drugs/supplements you take have an effect on. Products termed as "metal chelators" may infact have some quite other interesting effects on the pathogens in your body. But only future research will tell us more about that.