IMy main issue isn't dust etc. unfortunately. I live on the California coast and salt air corrosion is a problem with electronic connections and tool corrosion, I use a lot of contact cleaner, so this might be perfect.
-- Ravenware
An idea taken from mil-spec electronics: cover the trace sides of the modules with some nonconductive substance, such as clear polyethylene hardwood floor coating or clear nail polish, to keep salt air corrosion off of them. Another idea, also...tape a pouch of silica gel inside the cab itself, and bake that out for, say, an hour at 150F after doing a gig in a damp venue. I know of a few techno guys who swear by that to keep humidity down inside their modular gear. Then all you'll need to DeOxit would be the controls and jacks, as the other measures deal with the basic humidity/salt issues.