I can't really answer your question from a scientific point of view but I can tell you my own experience.

Cilantro:

I tried taking cilantro when I still had 3 amalgams in my mouth. I only took one fresh leaf before I went to bed and woke up feeling quite toxic. I didn't realise it was the cilantro so I kept taking it for the next two days. I felt very dehydrated, anemic, acidic, and toxic. About a week later I had my amalgams removed and then tried the cilantro again but it had the same affect. It took me about a month to recover from the symptoms that the cilantro caused. So my conclusion is that it definitely stirs up the mercury in me.

Chlorella:

A few months later I tried chlorella. At first I tried the wrong species in powder form which apparently stirs up more than it binds. It gave me really vivid almost hallucinagenic dreams, I had to stop taking it. I then bought some of the correct species in tablet form and it had a similar but not as strong affect. So I also stopped taking it. That was about a year ago and I just tried taking some more the other day and immediately I felt tired and went to sleep and had vivid weird dreams again. I also felt a strange sensation across the top of my head which I also felt with NDF (as I explain below). So I would say that chlorella also stirs up mercury. But it seems to have a slightly different action. It appears to detox through the colon rather than the kidneys, unfortunately neither my colon or kidneys function particularly well.

NDF:

NDF has both cilantro and chlorella in a 'nanonized' form (I think it just means the product has been predigested by enzymes). NDF affects me about the same as fresh cilantro leaf. I feel very toxic and dehydrated and need to drink lots of water. I also get a strange tingling sensation across the top of my head. So I would say that it also stirs up the mercury. In fact I used NDF as the chelator for a 24hr urine test which showed up 6ug of mercury. I found that taking micro-filtered Whey Protein Isolate powder and cysteine tablets helped considerably, but after about a month a felt quite acidic from all of the protein.

I have just found out that I have 3 tiny amalgams in the base of my front teeth that have been covered with composite. Perhaps that could also be contributing to the symptoms I am experiencing with the cilantro and chlorella?

With regards to DMSA, I haven't tried it myself, but I believe that it is potentially just as dangerous as cilantro or chlorella. The difference is that I think more research has been done with DMSA to determine safe protocols.