Vegetable oil will degrade over time, just look at the threads on a 5 year old bottle of any type of vegetable oil. However mineral oil should work well, just a drop or two spread on the surface with a lint free cloth. I use those cheap $1 microfiber cloths they sell for eyeglasses.Finish it off with a dab of vegetable oil for the polish. Seriously, vegetable oil works amazingly well. Of course, keep the vegetable oil off the threads and other contact points for the battery and your topper of choice.
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