Hey everyone! I had to share this information that I learned from watching "My Cat from Hell." Jackson Galaxy mentioned Fizzion on one of the episodes where the couple was dealing with (among other things) their cat's urination on on the walls throughout their house. One of my cats has been marking his territory because of a stray we adopted, and I've used EVERYTHING to try to get rid of the smell (I even tried Sporocidin, which is like a biohazard cleaner, to no avail). Well, I ordered Fizzion from Amazon and it arrived today. Holy cow it works almost instantly. I would smell the urine in the carpet, spray the Fizzion, smell again, and the smell is G.O.N.E. I practically did a dance of joy. So if you've been struggling with marking troubles like we have, then I think you'll be very pleased with Fizzion.