Corroded clew blocks

[HCA]

On my Beneteau Oceanis 331 clipper the aluminum wheels of the clew blocks in the sail of my single line reefing system have corroded so badly that I can not get them loose. Sinde I do not really want to take my sail off, I was wondering what options I have to get my reefing system smoothly again. I was thinking of tying new blocks through the old clew blocks. Or does any one have other suggestions ?

 

[lpdsn]

Try pouring a kettle of boiling water over them.

 

[Egbod]

I have had success with ACF50, it is an anti corrosion fluid and it solved an identical problem for me. Having been left on for a few days the pulleys would spin.