I'm only including this because there is such a demand for the method. I personally would NEVER smoke the tarry residue from a dirty bong or bowl, but I understand that sometimes we find ourselves in an unexpected dry spell and needing some medication.

This isn't something you should get in the habit of smoking, particularly if you have a compromised immune system or history of respiratory troubles.

I've seen methods for this that are very similar to an isopropanol hash extraction, but I don't like these because you end up co-extracting a lot of 'unknowns' which end up in the end result.

Instead, I'm going to give the method which is more like a liquid-liquid extraction that I use to 'wash' the undesirable co-extractates such as chlorophyll out of my cannabutter before using it in confectionery.

This takes advantage of the fact that the tars and resins are NOT miscible with water- different from a cleaning procedure, where you want them to be. So we are not using a carrier solvent at all.

Take a clean stainless steel or glass saucepan and put something in the bottom that will lift your pipe up off the bottom of the pan to prevent accidental overheating from contact with the hot surface. A tuna fish can with a couple nail holes punched in it is fine. You might want to run it through the dishwasher first, lol!

Now put the can in the pan, and fill it most of the way with hot tap water. Place the pipe to be cleaned on the can, and set the stove on low. You can manipulate the pipe underwater with a pair of BBQ tongs. Heat up the water to a simmer and periodically swish around the piece. You'll see tarry globs start to rise to the surface, and the water will get nasty looking. All the ash and plant matter is going into the water, and the tars and resins are collecting on the surface.

When your pipe appears clean(er), swish it one last time and remove it from the pan. DO NOT RINSE OFF!!! ALLOW TO FULLY COOL BEFORE CLEANING ANY MORE!!! THERMAL SHOCK WILL BREAK YOUR PIPE! Turn off the stove and let the water cool until it is safe to work with. Now take a glass baking pan such as a small loaf pan, and scoop off the obvious globs that are floating on the surface, and pour them into the pan. It's okay if you get a little water in there too; you're going to let it evaporate off. When you've got all the globs, discard the dirty water. There is NOTHING you want in that water (arguably, there's little you want in the tar either)!!! It's like super concentrated used bong water- GROSS. You're after that brownish-amber greasy substance in the pan.

Leave the pan in a warm place to evaporate whatever water you accidentally got in there, and when it's dry, you can scrape it with a razor blade. But seriously... it's not really all that desirable.