I used to get the same problem with the mast parts getting stuck together.
NEVER anymore! 
I just wrap a short piece of brown sticky tape (the sort you use for packing parcels)around the (clean) join of the assembled mast before rigging. Easy to remove afterwards and not messy.
Works a treat every time, and you don't have the problem of the 2 parts becoming detached during rigging/derigging.
Problem solved!
Cheers, Max