Do you mean just spray the exterior? What about the inside? Flushing the bearings out?
If you just spray or rinse off the outside, you will NOT be happy after pulling your nice reel out of storage before your next trip. It will feel and sound like a box or rocks. I know from experience. If you are fishing from a pier or boat, you might be ok with a rinse/spray, but defiantly not so if you are wading or in a yak.
Think about it… When you are spraying or rinsing something, where do you think all that salt h20, sand, and grime ends up? Inside the reel! The more you spray/rinse, the deeper that gunk ends up inside the bearings and inner parts of the reel.
Open the reel up and clean everything with a degreaser. Let it dry. Lube everything up with grease and oil (not a lot), like I described above. I have been applying a light coat of Corrosion X to the inside and outside of the reel by spraying a little on a rag and wiping the reel down.
You will have a reel that feels like it just left the shelf once you are finished with this process. Don’t knock it until you try it… Trust me.