This stuff is great! I recently moved into a new rental house and the previous tenants didn't clean very well, and the window frame in the bathroom had a lot of mold around it. I sprayed this stuff on it, let it sit for five minutes, and it completely cut through all the mold and left it clean and shiny. My only problem with this product is that the smell is very strong, but you're going to get that with any product that has bleach in it. It's certainly not my everyday cleaner because I prefer to use more natural products, but for tough stuff like that, it works like a charm.