ISO alcohol highest percentage u can get and put some kosher salt shake. Well let sit shake well. Rinse and repeat if needed works best that I’ve found that can’t be reached with pipe cleaners. Chunky salt is the trick with out it it takes much longer and many more shakes and repeats lol.What do you use to clean your rigs? I tried everclear and then isopropyl and only removed a little. Was going to boil but 1 of them has stickers on it so cant with that 1 lol.