BoeShield T-9 ... best protectant I've ever used in over 40-years of boating in salt waters ...
Just DO NOT spray it on anything that is dynamic or is supposed to move. I have seen it gum up interlock switches on the OB controls (neutral start safety, etc.)
Dielectric grease works too! And I always put that on any electrical terminal 1st anyway. Buy it from the auto parts store, as you can get a tube with 3X the amount, for 1/2 the price, as that sold in the marine stores.