When we first had our cats the mother cat had a problem where she would pee on the sofa. We've managed to stop it now but I can't get rid of the smell. It's fine till you sit on it then it stinks to high heaven.
I've tried washing it, I've tried using febreeze on the fabric part under the leather IYKWIM and it's beyond a joke now. I purposly put things on that part when we have guests so they don't accidently sit on it.