So I have this bong, right? Now, like every bong it gets rather nasty with heavy use. I started off using the classc IPA and salt combo, but I was never really satisfied with how clean it came. The experiments then began: I tried every salt you could think of; kosher, sea, table, pickling, but it always had that resin line man. I started bringing my IPA to a boil before using it (I actually recomend trying this if you have not already. Put it in a clean aluminum beer bottle and put it in a boiling water bath obviously wel away from sources of ignition.) but still it was dirty. I hung my head In defeat as I had lost the battle agaist filth. However, I shant lose the war. After attempting to order nearly 100% pure acetone from Sigma-Aldrich, and after I failed, wrote them an email, and never heard back I decided my next best bet was "100% pure" lie-on-the-label, acetone from Walmart. Now, for reasons beyond me they load it with Bitrex (denatonium benzoate), the most bitter thing on this planet. I assume its so someone doesnt drink it, but it acetone. who in the hell is going to drink that? The acetone and table salt combo is the cats pajamas, honestly. Not one speck of grime is left behind. However, what is left behind is a collection of particles of Im not sure what on the bottom of my beaker. Said particles are insoluble in water, acetone, and IPA. They can be brushed out but thats nearly impossible. I have three theories: one: something in the salt that is not NaCl is reacting with the acetone; two, something in there is reacting with the Bitrex using the acetone as a catalyst and what is left behind as a product of that reaction in the form of an insoluble percipitate; three, my extremely hard water is somehow to blame.