I have a beautiful marble counter top on the cooking island. It was never sealed properly and, of course, having the stove top in it, has a few stains. Everything I've read says it needs to be resealed at least once a year -- but no one says what to use. I've bought granite/stone/marble cleaners, that do nothing at all except waste money. Please -- someone direct me to a product/instruction on how to clean, buff and re-seal the marble.