I've been using Simple Solution for years now and it really seems to get out all of the urine smell. I use it when one of my cats sprays the inside of the covered litterbox. I've also tried Petzyme which I bought at Petsmart and it also works very well. There's also a product called Folex which you can buy at Target and a few other stores. This product is odor free and I've tried it a few times but it didn't work too well to mask out the odors when they throw up and I'm not sure if it would mask out urine odors. Good luck. I sure hope that something will work.