When I took my old Compact to the gun shop with this problem a month or two back, this is the procedure they tried first, and it worked!
My one (1989 vintage) lived for most of it's life in the packaging it came in (Formed polystyrene and cardboard) In a wardrobe at the seaside - wooden bungalow. Often frozen as the bungalow is not heated. Only recently moved to a warmer house and put in a padded locked case. Seems fine.
Lovely gun BTW.