I believe it is 2 parts peroxide to one part dawn or any dish detergent with a degreaser. I use an old small size dish soap bottle and just do 2/3 rd of peroxide and 1/3 soap and shake it up. This way I can squirt directly onto the stain. I have used it on carpet when I cut my cats toenail to short and got blood on the carpet, I used it on my scrubs when I worked at the hospital. Use it for neck stains on my friends shirts and underarm stains. works great on most anything. I don't use it on dark clothes like black or navy pants however. When you put it on you can actually see the stain lift right up and disappear. I had blood stains on a really nice new kitchen woven seat cushion, I was upset. I zipped it open and put a towel under and did it slowly little by little and it disappeared, never came back as they sometimes seem to reappear softer a bit later. It works best when the stain is new. I tried it on really old set in stains from the past, Some come out and some never do.
I have never tried to use it on chauncey's paw where he has a rust like stain there. Think I might give it a try and see what happens. The groomer never seems to get that stain out. She says it is from licking but I never see him licking his paws.