If I were you, before doing any chelation I'd get well acquainted with what Andy Cutler says on the topic. I read several horror stories about chlorella and cilantro. I used chlorella a lot when I started to fall ill years ago and it probably made me worse.
I agree w/XRunner on this -- google Cutler and either herb, and you'll find the horror stories. In fact, here's one:
http://whatidontknow.net/blog/eight-years-and-counting-my-chelation-story/
Although there are arguments and disagreements about what is 'safe' and the 'right way' to chelate -- or if it's even necessary -- I'm actually thinking of trying it again. I had the hair test done in August 2009, tried a few rounds of low-dose ALA chelation, and felt "fine", like I could handle it okay.
I took that for granted I guess, as I stopped the protocol (one does have to get up twice during the night) and in hindsight, wish I had continued, as I seem to be having a difficult time with methylation. I will be 'okay' for a week or two or three -- then get too irritable, anxious to the extreme, restless, uncomfortable...and exhausted. In fact I'm now so bad off that I'm not sure I could get up twice a night for chelation, but am still thinking about it, because my toxic load (mercury, arsenic, antimony!) could be the reason why I can't seem to tolerate the mb12/folate very well...???
Cutler is extremely opinionated however, and can be quite intolerant at times. Very anti-methylation...