Go to a head shop (smoke shop) and buy 420 cleaner. This is the best shit. Start off with a zip lock bag with some of the 420, put your glass pipe in with it and shake it up, this will loosen up and clean most of the resin. Rinse your peice with luke warm water, close all openings with your fingers, shake it with some water in it. Now to get the hard to reach resin, pour some 420 cleaner right in your pipe and use Q-tips to scrape out the rest, repeat shaking method with cleaner and with water. repeat the q-tip method until your piece is sparkln'....your going to be surprised how brand new your piece will look