sail cam roller seizure

[Barker]

I have a speed sail where a roller on one of the inaccessible cams above the boom has seized onto its spindle and won't spin after much salt water use without fresh water flushing. It can be reached by putting hand and arm up the luff tube but I can find nothing to grip it with once reached. I've dripped in a penetrating oil using a syringe through the luff tube and then left to penetrate but still the roller is rock solid. I know from unseizing quiver bag zips that salt residues can form an unbelievably strong 'cement'. Any suggestions on how to free the roller would be gratefully recieved. Many thanks.