I use Salt Terminator and you can purchase it from BPS. It's blue in color and comes with a nozzle to hook up to the hose with a bowl on the bottom for the solution.
We stay at Shell Island fish camp and the river out to the gulf is fresh water. I have the raw water wash down on my boat. So, on the way back in we would squirt the boat and all of our rods down with the salt stuff.
It prevents damage and cleans the salt away from where ever it is sprayed. It's like it leaves a film on things when sprayed. I've used it every trip and not have any problems later with my gear. You can also hook it up to your OB to flush it out too.
