I have tried rug doctor pet urine remover both in my carpet shampooer, my floor steamer and by spraying it on myself and washing out with a damp cloth. The urine smell is still there.
Also what will deter cat from peeing there again as he has done it a feels times in the same spot. He is 3 years old and was neutered at 6 months. He has two litter trays which he uses but if there is even a drop of his own pee in one he won't use it. I change the whole litter several times a day but can't always be there between pees/poos to get it done before he needs to go again. He sometimes uses the bath or the shower tray which I don't mind as it is easy to clean but the carpet isn't.