Good Morning, Mr. Clu!
I spent three years as a flight instructor with VT-28 at NAS Corpus. Prior to that I was the Aircraft Division and Corrosion Control Officer in an S2 squadron. Based upon my training and experience I would suggest two things.
First, protect all metal surfaces with an appropriate barrier (plastic was less in use in my day, but I would suspect it should be protected, too). Paint or wax or oxide, whatever is best suited to the surface involved. You might talk with commercial operators in the area and see what they use.
Second, perform regular and frequent fresh water washdowns. Use of soaps or solvents is problematical, in that they can remove some protective coats as well as the salt residue. Generally all you really need is water. I would be careful about using too much pressure (like a 1500 p.s.i. pressure washer) as that, too, can remove protective barriers by friction (vice chemical).
You probably already know that getting the unit under cover is the best protection.
If you don't have a garage or pole building or something else you might look at one of the many "soft" covers on the market. Of course in the Coastal Bend be sure to tie it down REAL well so that it does not end up in your neighbor's yard (and that "flapping" of the edges does not abrade nearby surfaces). I'm sure you can find a retire boatswain (aviation or otherwise) to help you out, here!!!
Corrosion control in a salt environment is a tough and ongoing problem. It's particularly bad in your area because of the constant, strong sea breeze and frequent heavy dews. But fresh water is your friend.
Good luck in your effort.
