I've looked around and there are no lack of theories for how to get rid of squealing tapes on playback. But every single one has counterpoints that make me hesitant to try them. I just bought some sealed tapes from Tapeheadcity and most played perfectly fine. One started squealing 2/3 through playback and now one of the others that played fine also squeals. I've tried some others and they play fine. So hardware seems to be good. What have you guys done? - lubricate? I've seen vegetable oil, car wax, sperm oil wax... - re-shell? but what if you want to preserve the printed shell? - anything else I haven't seen?