Why the smell keeps coming back
Surface cleaning fails on pet urine for a straightforward reason: what you can see on the carpet face is a small fraction of what is actually there. Urine soaks through the pile, through the backing, into the pad, and frequently into the subfloor beneath. As it dries it leaves crystalline salts, and those salts are hygroscopic, meaning they draw moisture out of the air. That is why the smell reappears on humid Huntington days and after any cleaning that adds water without removing the deposit. Masking products and scented sprays make the room smell like perfume over urine for a few days and then you are back where you started.