Every once in a while when I do an open house, I go in ahead of time and wipe down the countertops if need be. I just use a damp warm cloth and dry with a towel afterward. I do this in my home. Warning to those who renovate/remodel their homes for resale. Get with a realtor to compare your home with others. Putting in expensive stone countertops may really improve your sentimental value and make your home look stunning but depending on the neighborhood market, may not be the profit maker you hope to have on your home to sell in the future. Like I said depending on the market for the neighborhood.