That's a great point Paul. It's important not to use the water in such a way that it gets inside the reel. Even freshwater sitting inside your gear case will rust out your reels.
Instead it's best to use a light spray to dissolve the salt off of the outside.
Also, don't soak them in a bucket of water either. I know that sounds like common sense. But I've seen a few reels messed up really bad by guys doing that.
Oh, and it's OK to wipe it down with WD40 if that's your thing. But it's not a good idea to spray it inside the reel or on your bearings. It can actually lift the grease and oil away from the metal that they are there to protect.
-Bob