Amazing results. We had ancient moss stain on our family tombstones but did not know how to clean it off. We tried using high water pressure sprays, and regular brushes with some success. However, this tool showed miraculous results. With just a spray of water and scrub, we immediately saw the resilient moss scum disseminate. This will be our go-to tool during memorial visits. We cleaned the scrub by soaking it with diluted chlorine and water (1:25) for 30 minutes afterwards. Hope it won't loose its efficacy.