I know that shaving cream works, but the experts are now asking people not to use it because of the chemicals in it. Many of the tombstones are very soft stone and the chemicals can hasten the deterioration. Sometimes taking a squeeze bottle of water & spraying the stone lightly from an angle will help highlight the lettering. Because many of the tombstones are in bad shape, please be VERY careful before applying anything to the stone. Some items are far more caustic than we imagine. Karen