This is not my work, I found it at another site. "I did a quantitative test with active charcoal, and I know believe that cleaning up with charcoal is better than redoing an A/B extraction, or any other method I've seen. I took 1 gram of the original lightest yellow dmt, from the first pulls. Dissolved it into 20 ml of clean naptha. It has to be in a hot water bath to dissolve in this small volume. I added 1 gram of active charcoal, the granular type used for fish aquariums that comes in a sealed silver packet. You use them to recharge aquarium filters. I shook it, and the solvent became very very clear, except for the suspended carbon. I filtered through whatmann filter paper and rinsed with an additional 20 mls of hot clean naptha. The 40 mls were evapped in a casserole dish to get .7 grams of much cleaner dmt. Pictured is the .7 grams after active charcoal cleanup, and a similiar amount of the original dmt. Based on finding 27% insoluble garbage in the original dmt, if the active charcoal got most of this out, then it is actually pretty efficient. I have done it several times since this. I cleaned up the rest of the 9 grams of cleaner original DMT. It looks like 1/3 equivalent weight of charcoal is better but that you need to let it sit overnight, the solvent takes a while to clear. just as clean but slightly better yeild with less ac. It also apprears to me that using active charcoal gives a slightly whiter final product than redoing an A/B extraction and then re-crystalizing. It is much much nicer to smoke the white powder. You can put a large amount in a bulb vaporizer, and hit it repeatedly over several sessions, and the place it vaporizes from doesnt even get a brown tint. The taste is much better than even the light yellow powder." I seen this thread and I found this very interesting and wanted to share it here. http://forums.mycotopia.net/showthread.php?t=18363