get some rubbing alcohol (isopropyl not ethyl) from your local drug store, make sure you get the highest percentage possible, where I live the best you can get is 91%. Then fill a zip lock bag with the alcohol and throw your piece in the zip lock bag, shake it around real good then take an old cooking pot dump the alcohol in the pot and then repeat this process a couple times until the piece looks as clean as possible. Now set the piece aside for later. Now open up all your windows or do this with a cheap hot plate outside take the pot and put it on the stove, turn the stove on a real low heat (lowest possible) and let the alcohol boil down... once the alcohol is boiled down you should have a sticky black substance (resin)... now you can take a razor and scrape that shit off the bottom and smoke it!... and then finally if you so please you can get some formula 420 and wash out your piece just to get rid of the rest of the stuff left behind but whatever you do make sure you let all the alcohol evaporate from the resin and the piece cause you do not want to be smoking alcohol!