Allergic to Sulfur- What Chelator to use

I am allergic to sulfur. What does Andrew Hall Cutler's Book recommend to use as a chelator instead of DMSA, if one is allergic to sulfur drugs?

Also how long after Amalgam removal and removal of toxic root canals and infected root canaled teeth does he recommend to allow for healing prior to beginning heavy metal/mercury detoxification?

Another question: what chelator may be used in challenge test for heavy metal toxicity - particularly urine porphyrins test?

Also important to note have advanced adrenal fatigue (stage 3) and fibromyalgia in addition to many other of it's sequela
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