Eck..... I dialectric'd (spelling?) greased all mine. I kept my mowers clean and wax'ed as much as possible. Rust can set in anytime, its wisconsin everything rusts, but keeps a professional appearence and shows that I take pride in my work and the equipment to accomplish that.
We did that for awhile until we realized that it didn't mean anything and it was taking up time. But we work 12 months a year. Our equipment trucks trailer is probably average compared to our peers. The connectors had diaelectric put in once a year with air clean. Fluid film the rust it happens here even though we are hot and dry.