I always coat everything with used hydro / motor oil blend that I salvage at changes I even coat my metal parts on my tractors with it! Painted surfaces and all.........I know it helps.......I see the results between seasons.
I believe what you are talking about is called plow coat. I have used it in the past but I have real good luck with grease myself. Plow coat seems to work real well too.
we always used grease from a bucket we kept just for that with a big paint brush. stays on even in the rain, comes right off soon as you drop plow in ground.