A container that is narrow and tall enough to completely submerge the glass piece.
Something small and thin to agitate the piece with, such as a cotton swab, piece of wire, string or stream of water.
How to Clean Resin Off of Glass Surfaces
Step1
Resin in the sticky, blackish, foul-smelling goop that accumulates on water pipes and and glass pipes. This substance imparts a foul taste when the piece is used, is unattractive and is plain unhealthy to inhale. Formulated resin cleaners are effective but also very expensive. Here's a much, much cheaper method that is just as effective.
Step2
Take a bottle of rubbing alcohol and pour it into whatever enclosure is appropriate for the piece at hand. Fill it to such a degree that when the piece is situated in the container, it is completely covered in alcohol. Then let it sit for a day or so, depending on the level of build-up.
Step3
After a day or so, the resin will loosen and dissolve to such a degree that it's simple to do the rest. Depending on the size of the piece, any number of objects may be used to physically remove the gunk from the glass. My favorite method involves using a stream of hot water from a faucet, which then carries the resin away on contact.
Step4
Allow the glass to dry thoroughly and do not expose it to extreme temperatures on either end of the spectrum. You are trying to save your glass, not put a Jack Ruby-style hit out on it. Extreme temperatures will fracture your glass.
Tips & Warnings
Avoid extreme temperatures.
Do not put this solution where children or animals can get near it.