Activated charcoal is a highly adsorptive antidote for emergency use (and a few other no-emergency uses), able to rapidly mop up toxins and chemicals. Toxins adhere or stick to the very porous surface of the charcoal, so nothing is absorbed by the body – instead passing through and out of the GI tract. It is a fine, black powder that is odorless, tasteless, and nontoxic, and it has proved its value over and over again.
But you have to know about it and have it on hand for it to do any good!
It was 1831. In front of his distinguished colleagues at the French Academy of Medicine, Professor Touery drank a lethal dose of strychnine and lived to tell the tale. He had combined the deadly poison with activated charcoal. (source) Need I say, please don’t try this at home!