There is a product called Nature's Miracle that is guaranteed to work. I tried it when we visited my son, as he was in temporary housing that had pets in it previously. This is when you get that infamous black light to show you where the stains are. Viewing stains via the black light is not for the weak-of-heart. Let's just say it doesn't only show up pet urine! Any black light will do, also. Pet stores try to sell you a special one, but any will work. Just pour the stuff on and as it dries the stains and odors are lifted. It worked great, but takes a while to completely dry.