1) Start by making sure to remove and loosen any resin, plant material, or bud from the pipe. Holding the pipe upside down or running hot water through it quickly are good ways to remove loose gunk from the pipe. Typically we let hot tap water run through the pipe for at least 20-30min. Also try filling the pipe up with hot water and shaking the pipe while covering the holes. This should loosen and remove the bigger chunks of resin and plant material still left in the pipe.
We recommend avoiding using things such as wire, stiff pipe cleaners, or other materials / utensils which could break the glass. This is especially true with the parts of the pipe which have thinner glass ie. the bowl, mouthpiece, etc.
2) Using a a plastic bag that will fit your pipe, fill it with isopropyl, rubbing alcohol with enough alcohol to for the pipe to be full submerged. 90% isopropyl is much better than the 70% solution. 90% will clean the pipe faster than 70% solution.
Add 1-5 tablespoons of salt to the bag with the pipe in it. Adjust salt level according to size of pipe and amount of alcohol. You’ll want it to be very salty. Salt will act like an abrasive sponge on your pipe, scrubbing away the resin in places you could never reach with a sponge or brush.
3) Shake the pipe in the plastic bag, making sure to work the salt into the inside of the pipe and into all the parts of the pipe. Use your fingers to close off the openings to the pipe and shake the pipe for 10+ minutes.
4) Once the pipe is visibly clean to your liking, take out the pipe. Using hot water rinse the pipe and rub the pipe down with clean paper towels.