Ammonia If laundering with detergent isn't enough to get tough stains such as blood, grass, or tomato sauce out of a fabric, try a clear ammonia-based spray-on window cleaner instead. (It's the ammonia in the window cleaner that does the trick.) And DON'T USE BLUE colored as pictured; get UNCOLORED Window cleaner to avoid staining the fabric blue.) Spray the stain with the window cleaner and let it sit for up to 15 minutes. Blot with a clean rag, rinse with cool water, and launder again.