I don`t have any old wives tales but here is something from a book called Caring for your Cat, written by Angela Gair in association with The Cats Protection.

Areas in which a cat sprays should be thouroughly cleaned to prevent `top-up` spraying as the scent weakens. Never use cleaning products containing ammonia or chlorine as both of these compounds are constituents of cat urine and the cat may perceive them as a rival marker and deliberately respray in response. The best cleaning agent is a warm solution of biological washing powder, which will digest protein in the urine. Rinse and allow to dry, then (assuming we are not talking about antique furniture) wipe or spray with alcohol, such as surgical spirit.

As for products, one which worked well with removal, when Ebby peed on the carpet one time, was Johnsons Carpet Stain Clear. But how it works for non return peeing I don`t know because I solved the original reason for her doing it (bought her an enclosed litter box ).

Chris