The things that have worked with Felix (see "peeing" below) are 1) putting the food dish where he used to pee 2) a new, large, superclean litterbox in the basement; he likes to be accompanied down there in the evening, and 3) spraying Feliway around the problem spots. The cat psychiatrist was a huge waste of money but she did suggest putting down an unpleasant surface like an old shower curtain, which sounds reasonable. Good luck!