I just heard a funny commercial. It was for a spray that gets animal smells out of fabric. They guarantee that even the worst pet odor with disappear! "It's just like magic!" the happy housewife crows. Then the voiceover said, "Even if your carpet is continually soaked in cat urine, this spray will make the odor vanish instantly!"
All I can say is, if your carpet is continually soaked with cat urine, it's time to think about getting a different cat.