Try vinegar, believe me it works, but you have to give it time. Fill it with vinegar making sure it has contact/soaking with the funky area. If you look very closely you might see very tiny bubbles streaming when it is soaking. That means it is working. I gave it a few days to a week, but everything was gone.
Chemists use TSP to clean glassware and it’s very effective. It is safe if you do it properly. Depending on how much you use, TSP in solution can become very caustic (alkaline), so make sure you wear dishwashing gloves or Nitrile gloves when working with the TSP solution (and acetone below). Rinse all parts of the glassware pipe/bong with hot water. It doesn’t have to be super hot, just whatever you get out of the tap. Then fill a porcelain bathroom sink with approximately two gallons of hot water and add 1/2 cup TSP powder and dissolve fully. Then set all your glassware in the sink to soak. Make sure you get all air bubbles out of the glassware so everything’s fully submerged. I usually do this before bed and let everything soak overnight, but a few hours is enough. Occasionally scrub the dirty surfaces of the glassware with thin flexible bottle brushes. After soaking and scrubbing, rinse everything very well with cold, slow running water (cold and slow works much better than hot and fast). After thoroughly rinsing, allow the glassware to air dry for several minutes. Then rinse everything with acetone and remove any final resin stains with a brush or pipe cleaner. Then allow everything to air dry before baking in an oven at 450 degrees (F) for 15 minutes. Allow to air cool before handling. Isopropyl alcohol leaves a residue that is harmful to breathe in and I never use it. Chemists use acetone because it evaporates almost completely, leaving very little residue, and the final baking process insures a safe result. Acetone is flammable so be careful and read the safe handling and use instructions for the acetone and the TSP. Ammonia based glass cleaner and paper towel works well to clean out your sink.
