I recall something about coating exposed poles to thwart rust, but my search was fruitless. A previous owner coated the pole pieces of my new (to me) 20+ yr old P bass with something, it's still on 6 of the 8 magnets, looks like some kind of amber gunk... whatever, it has worked for the most part, but looks like the remaining dots will be coming off anytime. What to do? Leave them alone? Rub off and keep them naked? Rub off and coat? with what? (was it clear fingernail polish I recall being recommended?