What is a good way to clean weed resin from a pipe?

A good way to clean weed resin from a pipe is to use a mixture of isopropyl alcohol and coarse salt. Fill a resealable bag or container with the pipe, add enough alcohol to submerge it, and then add a couple of tablespoons of salt to act as an abrasive. Shake the container gently for a few minutes, then rinse the pipe thoroughly with warm water and let it dry completely before using it again. For stubborn residue, you may need to repeat the process.