Hi cla6665
I made a fake rock wall for my girl friend and sealed it with 2 coats of diluted Elmer's Carpenter's exterior wood glue (pva base). First coat I did was a real thin coat. I had painted the rock wall before I sealed it. I like that it did not leave a gloss finish and it really toughens up the grout. What I did not like was it gets tacky when you scrub it with water. Its almost a year old now and still looks good. Lelu our dragon luvs it. Is it safe - yes, does it look good - yes, is it easy to clean - tricky, Next time I will search for some better sealer but most likely it will be to expensive. We do need a good Sealer and Paint page so we know whats safe and works.