To me, spraying them with water is just silly if you're doing this regularly. Moisture is the major element you're trying to take out of the equation.
I know many of the OEMs have so nicely included "wash ports" to their cutting decks. What a nice thing to do. Now you can get everything wet including bearings, electrical components, etc..
Just adding to all the above, but you want to keep things DRY. If you can give the deck a quick scrape-down, blow the whole thing off after each use with your leaf blower and then store it in a dry place, out of the elements, you're going to be way ahead of the game.