That's right; not an absorber, but an adsorber, which means that instead of sucking in the toxins and becoming one with them (as in the case of absorbtion), activated charcoal holds onto the toxins on its surface and transports them out of the body.
Activated charcoal is negatively charged and attracts positive elements like some toxins and heavy metals. This is one reason why it makes an excellent water filter.
It is suggested that a tablespoon of activated charcoal per day can set the body on a mold detox, as mold is positively charged. If you were to embark on a cleanse of this sort, triple your water intake to help flush it out. Also keep in mind, it is not a long term solution but a short term detox (one to three days).
It can also be used to bind and remove lead and mercury from your body. In conjunction with probiotics it can be one of the best heavy metal detoxes you can find.
The third great use for activated charcoal is to help someone that is experiencing alcohol poisoning. Swallowing a tablespoon of activated charcoal will allow it to bind to the alcohol to get it out of your system.
For these reasons (and more, including whitening your teeth) activated charcoal is one of best short-term detox materials you can get your hands on; and it's cheap! Do your own research on it and find out if it's something you can use; don't take this article as your only source of advice on the issue, but don't let a lack of media attention turn you off to it.