I am just glad that I got some new riding boots as a wedding present. The ones I had before were peed in by a bad kitty I used to have that would pee in my closet if he got locked in the house. They were expensive boots and I didn't want to throw them out! I washed them and washed them... got them to where they didn't smell at all! - Or so I ~thought~. Once I'd been in them awhile, and they warmed up and/or got wet with either sweat or water... POW! the stink would hit. That cat just ran off one day.... I swear I didn't kill it!
I was reading your post about the stinky boots that the cat peed in and I almost spit my coffee out. There is one place in my tack room where the cats peed when they accidently got locked in. It's a cement floor but that smell ain't coming out. It's not too strong when the air is dry but if it's raining or humid you can't hardly go in there.
I swear, cat pee smell is impossible to get rid of.