Cat urine and spray contain ammonia, a powerful and persistent odor which is not easily removed. Regular cleaning will not fully remove the odor, at least not to the point that your cat will not still be able to pick out the smell (cats have an extremely keen sense of smell). In order to remove all traces of urine or spray you will need to use an odor neutralizing solution. Such a solution breaks down the ammonia and other protein based elements in the spray and urine into innocuous chemicals that your cat will ignore. Such products can be found at your pet store. In using these products make sure to follow the instructions very carefully. In many cases you may need multiple treatments to completely remove the odor.
If you feel you have cleaned an area thoroughly but your cat is still spraying there, if your home still smells but you can’t find the source, or if you are uncertain as to how clean an area is you can use a blacklight. By shining a blacklight on an area you will be able to see if any urine or spray remnants remain (such items show up as bright yellow under the blacklight). If you see such an area you will need to clean it with an odor neutralizing solution. If you do not have a blacklight at home you can usually rent one at your local pet store.