AMAZING stuff. Worked really well at getting out some difficult stains. Still trying to get another area clean, but I am confident it will work. My rescue has been marking since I got him a year ago. I love him so much, but beyond frustrated with the pee stains in my room (carpet) and my living room (area rug). He goes to the same spots to mark, so its been accumulating for a while. I just bought a carpet cleaning machine, and a gallon of MPP for the machine. I originally started with the spray bottle which I went through in a few days. I hope I don't have to do this much longer, but glad that I have found MPP. I have bee recommending it to all my friends. A great find!