letting a light oil soak into and thru the freewheel will do a few things. it will rinse out the old gunk and lube the mechanism as well. Don't worry about snow/slush cleaning out the lighter oil as it's internal and protected. You can do a pre lubing with WD 40 or varsol, etc. if you feel the need. A 5-W30 motor oil is light enough for most winter needs.