Unfortunately, I am of the opinion that there is not much you can do about it. I've had several experiences with cats and houses. The first was a rental when I was a kid. They had a cat that "lived outside" but had obviously come in periodically since every time the house heated up (in ARIZONA!) you could smell cat urine in several of the corners (always the story about having the carpets cleaned etc). Second, my parents just recently purchased a new home from a man who had a cat which lived INSIDE. They were told the carpets had been replaced, cleaned, etc and that there was nothing to worry about with the cat. They were shown receipts to prove this. THey were told it had been kept in the garage since the new carpets had been installed and it did appear to be true. (as much as you could see, all the cats belongings as well as the cat were always stowed in the garage) They visited the house TONS times and it always smelled OK. Well, once they moved in and his furniture and air fresheners (we discovered about 30 of them in places that would have been behind his furniture)were gone it was apparent that he had been lying. The carpet was new (as of a few months) but, again, in places where his furniture had been stragegically placed there were spots, spots and more spots! They had the carpets cleaned (even though they had been cleaned AGAIN prior to the signing of the papers), re cleaned and finally gave up. You could not go anywhere in that house without the stink. You could not sit on the floor without bringing the stink with you. Your clothes, body, everything would stink like cat urine. We came home from a visit, opened our suitcases and were hit with a smell of cat urine. Finally, after a month or so they gave up and ended up replacing the entire house worth of carpet. I wish I could send you the pictures they took of what the backside of this new, and VERY washed carpet still looked like! It looked as if someone had walked around the house with buckets of pee and dumped them out all around the house. It had not only stained the carpet and pad but once they had those ripped up they had to SCRUB the floor boards below them with bleach several times as they were also horribly stained and stinky. It took thousands of extra dollars and several days of ripping and scrubbing but they finally have a clean house. My point is this: The stink will ALWAYS be there until the floor is overhauled from the ground up. Our house in Arizona smelled like cat urine just as much on the day we moved out three years later as it did on the day we moved in. No amount of carpet cleaning, air freshening or waiting it out will remove that smell. Apparently the scent this man used will mask the odor but it was obviously still in the carpet as the smell came off on us! Would you want your child playing and laying on carpet this unsanitary? You will have to have them rip up EVERYTHING and disinfect and scrub the floorboards and start over with new carpets. If I were you, I would keep looking. Sorry - and good luck!