I know when I am trying to get smells out -- like when someone has thrown up -- I use baking soda in warm water & sponge it. It works really well. I've never had a cat so don't know if this would work the same. Would be worth a try. When my son & family moved into their new home, it was very clear the dogs (she was a breeder) had had the run of the house. The carpet was pulled out & the carpet layer said he had never smelled anything so bad. He suggested she was the floor (concrete) down with clorax water. She said she went thru the whole house 3 or 4 times before the guy came back to lay the carpet. It did help a lot. I know you can't use clorax on the quilt, but if you need it for concrete, it will be worth a try.