Well, simply put, (in general) you need to expose enough of the pot in order to shoot deoxit into it. Most pots have some sort of slot, hole, crimp or opening of some sort of breach in it's design where you can point the straw to inject the solvent. If you are wondering whether simply removing a knob is going to be enough, it won't be because the pot body won't be accessible at all. If all you do is spray the shaft, then all you are going to do is strip lubricant from the shaft loosening it up, and forever lose that new smooth feeling which can never be restored short of opening up the pot to relube. Some pots are sealed. In that case, you won't be able to get the solvent into it.