I get a similar problem for maybe a minute (always seems like longer!) and then it lets go. I just persist with wriggling it about and trying to change the angle of the join until it cooperates. I think it's rather airtight and air is not getting in quickly enough to draw the parts apart. If that's it, then any grease will just prolong the agony. Persistence pays off in the end.
You should not need any lube on the joint. I would wipe the male and female sections before joining. Clean with water if required. You could also try some electrical tape on the joint. I do this with my windsurfing mast to prevent grit getting into the joint.
Okay, I know I should be able to twist apart the upper and lower mast parts after sailing, but I just don't have any strength left!
Can I put some sort of spray lube on them so they'll come apart more easily? I'm thinking along the lines of McNutt Sail lube.
