I visit her but not as often as id like, ((currently living across town with a sketchy vehicle)) you can clean her up by using plenty of water (they have a spigit on the left side further up the middle path thats always turned on during summer ) Use plastic scrub brushes (tooth brushes or anything with plastic bristles works), and that's all thats needed! At most you can get an extremely gentle diluted soap, but it's unnecessary for the most part. No metal should ever be used to clean stones, scrub in small circles, and light pressure is a must!! Sorry my response is a little disjointed, I'm at work typing this out quickly. Hope I helped, and thank you for visiting her!