I've had many vintage pots apart in attempt to save them. I have not tried this but I believe the cleaner is to sit in the chamber as the you turn the pot. Allowing the cleaner to seep by. No way as good as directly spraying them. But with those models without a back plate if you have to take one pot out the entire assembly has to come out. If this can cure it, it's 1hr of bench time the guitar owner won't have to pay. So for $9.00 it's worth a try. If they're really bad then yes I agree removal and disassembly is the only way.