James, I recently cleaned two carpets for an elderly gent who sleeps downstairs and uses both carpets as toilets(The house smelled like a gents toilet), one of them also having solid black areas near the kitchen and his arm chair. I hit them both with M power at 120 to 1 and agitated with a scrubba deluxe. I used plenty of pre spray and did them both twice then I went outside to the van to start setting up my equipment, as I walked back indoors I noticed the smell- it had completely gone. I extracted both carpets, smell gone, black top gone, carpets beautiful and smelling fresh, and I was going to use an odour remover after cleaning but it was not needed. Try it. Mike