Cutler is a chemist - and he's real into the known, measured chemical actions of different molecules. ALA has a known chemical makeup. You can measure and quantitate its ability to bind to mercury and the time that it remains in the body (ie., its "half-life"). Cutler's protocol is to take ALA every 3 hours! even at night! (so you have to wake up at least twice/night) for a few days and then a few weeks off...
he does it this way to maintain a steady blood-plasma level of the ALA during the "days on" - the theory being that the ALA will bind and mobilize mercury and bring it out of your tissues and even out of your brain. but it does not bind tightly (btw NO CHELATOR binds tightly). Any chelator will bind mercury molecules and then drop them randomly. The key to actually eliminating the stuff is to keep a steady dose of new chelator in the blood to mop up the molecules that have been mobilized but then "dropped" by the chelator - if that makes sense.
so, IF you are mercury toxic, and you take ALA in a big dose, 1 / day say, and you kept it up for a while - you would expect to feel worse. you are basically mobilizing the mercury out of your tissues, but not keeping a high enough level of the chelator in your blood to remove it - so the mercury gets redistributed to other tissues where it does fresh damage... if you feel significantly worse on a single dose ALA - you probably do have some mercury problems.
the reason that Cutler says "chlorella kills" is that its pharmacokinetics are totally unknown... what is its halflife? how much mercury does it really "chelate"? does it mobilize more mercury than it binds? No one knows these things. (we do know scientifically that cilantro definintely does chelate mercury, btw - but no one knows how or what its half-life is or how to dose it safely, apparently - Cutler thinks cilantro is really dangerous.)
now, this is all JUST THEORY. we think we know so much - but no one really knows how all these delicate interactions work... I haven't read any posts from people who say they got worse on chlorella - just the contrary. It's interesting you say you did read one. But Cutler gets tons of email from folks messed up on chlorella and cilantro cures (at least, Cutler SAYS he does...).
What's dangerous about merc. tox is that the effects can hit you gradually or later on, depending on what tissues/organs your body decides to dump the stuff into... i imagine if you were getting more merc. in your brain, you'd feel an increase of psychological type symptoms, but I don't know. I wouldn't really worry about it.
I mean, you have to calm down (or at least, I clearly need to calm down :), and remember that ALA is sold over the counter and thousands take it everyday without dropping dead. Thousands of people are taking chlorella too - its a popular supp. If it were really sooo bad there'd be reports, don't you think? Also, people in Asia and Mexico and other places eat large amounts of cilantro every freakin' day! How dangerous could it really be?
I dunno. i typed too much - i'm racing again tonight. sorry. all i can say is don't let a bunch of egg-heads stop you from taking something you feel is so good for you - but have as much knowledge about it so that if you do have a negative response - you'll know which supps. to suspect...