[Arran]

Usually, if I am overhauling a radio, I am pretty close to taking the volume control out anyhow with having to replace caps or resistors around it, so if it's stiff, or dirty, I pull it out, dismantle it, and clean it out manually with rubbing alcohol. I leaned to do this when working on old farm battery radios, such sets usually sit untouched for decades, even a lot of the sets I repaired have been sitting unused for a decade or more, so the controls are pretty gummed up, even in the bushing the shaft goes through.
Regards
Arran