Good luck! There is a lot of good advice here. Please keep us posted what you finally did. I hope you can find a cleaner. I would hate to have to cut out a piece and re-piece it! After treating and washing, hanging it outside couldn't hurt. You didn't mention if your cat is neutered. If not, it will really reduce the smell of his urine. Tomcat urine is very nasty. Sometimes neutering stops the spraying, but probably not if he is an older adult and is doing it because he is upset. I feel your pain as I have three cats who I love dearly. Thankfully they all get along and no one feels the need to "mark". Good luck again!