to grease or not to grease

i have the white grease spray that works well to apply to the internal moving parts, just a spray film on it works well. i also have the plastic/nylon disk so no grease on the plate. I also got a hitch cover on Amazon with blemish for $20 bucks. keeps dirt and crud out and off. Dirt is not good for it as we know, and WD-40 may attract dirt etc. Good Luck & Be Safe ! ! !