You can absolutely eliminate any residual moisture with a quick dip in acetone, after the metal cools a bit. That's one of the few things I remember from high school chemistry, and it eliminates the alleged varnishing that is attributed to WD-40. Just make sure you get a thorough coating of light oil on the entire mechanism. I think a dip in Ballistol followed by some compressed air and a complete wipe down of all exterior surfaces could be the ticket. You can also mix Ballistol with water (50/50) to achieve a light oil film, but I'd be reluctant to reintroduce moisture to the mechanism unless I baked the parts at about 240F after oiling to evaporate any remaining water and leave just the Ballistol film.
