[smithb]

My father was the manufacturing engineer in charge of making weatherstripping for GM (then Delphi) at his plant. He then moved to be the global manufacturing engineer manager for engine mounts, so my info is at least 10 years old, but he said to use silicone lube (when he was at my house he bought some Penske lube stuff I still use). But you need to spray it on a rag or paper towel. If you spray it directly on the rubber the propellent in the lube will dry out the weatherstripping. The main thing is to make sure what you use is silicone based, since it is silicone rubber. Siloxane is what they soak them in after extrusion to moisten them, so if you can get that (which I could at my old job), use it.