I bought this product about one month ago not knowing if it would really work. But,believe me it does work. I used it on old pee stains. Coffee stains Blood stains potty stains and like they say Spray and let sit for a few hours. Maybe even over night. I have used one bottle and have ordered 2more. My Dog is 15 years old and has a lot of health problems. This product has been a big help. Thank you.