I used to own a white couch and I loved it. That thing really did get quite dirty but I was always able to get it clean again, not because I had some top secret cleaning recipe, but because it had removable slip covers! Such a lifesaver!
Dog Urine Odor Be Gone! Tested and proven. All you need is a water bottle + + White Vinegar + Tide Detergent. Use 6 oz water, 2 oz Vinegar and 1 tablespoon of Tide. Squirt on affected area and Voila, odor should be gone in less than 24 hours!