I use this all over the house. Inside and outside on stucco and concrete as well as natural stone. My latest use was the out side of my LQ horse trailer (RV). As you can imagine it gets filthy. On outside as well as horse part. Krud Kutter cuts right through grime that had been building up for years. All I did was spray half strength on and let sit for a few minutes then using a bucket with about 2 cup per gallon use a sponge to scrub. My trailer looks amazing. It worked amazingly well on dried on horse poop and pee spots. After using krud kutter along with a power washer you cannot tell my horses actually have ever been in there. For tough jobs you let it sit then use elbow grease and it works better than anything I have ever tried.
Kansas City Mo