Living in Florida you sure can use it. I used to live in Brunswick, Ga so I know exactly what you are dealing with but I didn't know about it then.
I just hd to replace about 2/3rds of the marker lights on the 76 Sovereign
because when I opened them up to see why one or both bulbs were not burning everything inside was rusted. The plastic (appears to be PVC) bases on the original was flaking away as well. Assuming they were PVC in warm temps in the presence of moisture give of chlorine gas which attacks metals. I noted in the mornings the inside of the lenses showed moisture which is the combo for a disaster in the making.
I sprayed the old ones down with ER as well as the new ones and soldered the wire spices I did and taped them when new ones added. As well I sprayed the bases of all bulbs before inserting.
Then I took outdoor calking and and went around the lens openings and tried to completly seal the crevice so we will see how long the lights go.
When I got it in I noted no right rear turn signal. I thought the guy might have got a pole wrong and was going to the front plug apart and see what gives. I had already sprayed the truck/trailer side connectors and then I spotted the round plug in AS. I pulled it off and sprayed the plug. Nothing changed. I went back and sprayed the male side on the AS and they started working immediately.
If you are going to have direct rain on applications for threads you might get some Lee Alox bullet lube and take a small brush and paint it on exposed theads. It is almost like Cosmolene. Another good grease is RIG bought in gun shops. It was fielded by military in WW2 to keep rifle bores from rusting in South Pacific as the weather was perfect and coupled with corrosive primers was a master disaster so this stuff was fielded. RIG is not only brand name but acronym for Rust Inhibiting Grease.