How to remove blood stains even after drying - 1. Pour hydrogen peroxide 3% on the stain and give it a good scrub with a clean rag. Let it soak for 5 minutes or so. 2. Take your hot iron and go over the spot until the stain disappears. You may notice a ring around where the peroxide was - just wet it with water from a spray bottle and go over it with the iron again. Voila!