A couple of things I've done with my sled since I am using it in the salt more than I have anticipated.
1) Zincs - I've got 5. ( go ahead call me paranoid ,I am ) 2 on the hull, 2 on the pump and 1 on the kicker. Remember to brush them occasionally with a stainless steel brush.
2) Run in fresh water after you are done. I dump mine in Lake Samm and run on the trailer for a few minutes. Run the kicker too.
3) After every use I do the following once I get home. Rinse with a product called Salt Away and then wash the boat with soap and water. I might be able to get by with just the Salt Away rinse but am afraid to take a chance.
4) Wax, Wax Wax - I do this about once per month.

So far this seems to be working. I go thru this ritual as I intend this to be my last boat and have seen 1st hand the damage electrolisis / corrosion can cause.