Cat urine dries fast, but the uric acid inside it doesn't go anywhere. It bonds to carpet fibers, grout, and wood at a molecular level and turns crystalline, which is why the smell seems to vanish and then comes roaring back on a humid day. Soap, water, and most store sprays just aren't built to break that bond. You need something that reacts chemically with the crystal itself. A spray that sits on top will not do it.