I already did 90+ rounds of cutler chelation for mercury in the past, so I think that mercury isn't the problem anymore. Cutler is right that Iodine isn't a chelating agent but nervertheless Iodine enhances metabolic speed and causes the bones to remodulate, that is the reason why lead come up when there is prolonged supply of iodine.

Look at Holmes et al: "THE EFFECT OF VITAMIN C ON LEAD POISONING" there it is stated that

“Renal excretion of lead depends directly upon the lead compounds circulating at the time in true solution in the blood. . . . The increased excretion (of lead) through use of potassium Iodide has been noted by previous workers, although others have failed to confirm it, chiefly because they confined themselves to the urine while the excretion is mainly in the faeces. The Iodide causes the reappearance of lead in the faeces from which it had been absent.”

So at least it is an investigation to be carefull that Iodine could loosening the tightly bound lead at bone-storagesite.

I have little to no experience with chelation, but I am inspired by the fact that we have a protein that takes care of the metal load; if, of course, you have the bricks to make it;

"Methallothionein is a protein that carries out very vital functions in the body. There are four different types of this protein. It is made up of 60 to 70 amino acids and 7 atoms of zinc. One of its most important functions is the protection against heavy metals. For this reason high concentrations of this protein are present in the mucous membrane of the intestine where it serves as a binding agent for heavy metals by exchanging zinc for mercury, lead, platinum, aluminium etc. "
http://www.cease-therapy.com/treatment/metallothionein


Metallothonein also plays an important role in several other processes in the body:

"It regulates zinc and copper concentration in the blood.
It is essential in the development and functioning of our immune system.
It is indispensable in the development of nerve cells (neurons) in the brain together with the Omega-3 fatty acids.
It protects against excessive yeast growth in the intestines.
It prevents intestinal infections.
It is involved in gastric acid production.
It influences taste and texture sensation of food in the mouth.
It has a regulating influence on hippocampal behaviour.
It is involved in the emotional development and socialization (amygdala)."

http://www.cease-therapy.com/treatment/intestinal-disorders