I used vaseline. For real. It's a mess but it absolutely seals everything from moisture. The least bit of humidity in the air will find it's way through every crevice in your wraps and sealing putty and somehow latch onto a critical part of your PC and mess with your mind.
I'd hose it down with some CRC electrical cleaner and let it air dry then slather it up with the white petrolatum...pack the socket (gentle dont's bend the pins) and after seating the CPU wipe around that locking mechanism and make sure there are no air gaps in or around any of the socket area.
returning to hibernation