You may live near some of my relatives and friends. I grew up in McKenzie. Three of my four cats are from McKenzie and one is named McKenzie, but I haven't lived near there in many years. Does the Tilex do anything to erode the old marble? I guess bleach and water would probably do the same thing, but I worry that it might be too caustic. Of course, I don't really know anything about stone or chemicals, but a lifetime of housework makes me wonder. Tilex doesn't hurt ceramic or porcelain, but I am not sure about marble. Have you checked back to see what happened over time? Just wondering. I wouldn't want to do anything that would harm the tombstones, but I sure do like time saving and convenience. Thanks for the suggestion. Peggy