OK I'm going to go nuts - please help me get the smell of cat pee outta my leather sofa

[LuckySalem]

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.

I have a special 'get rid of evil cat smells' product - got it at the pet store. I think there are a few brands, but they do seem to work ...

Biological washing powder is supposed to be good for getting rid of cat wee smells

thanks all