They also make a pheromone collar, much like a flea collar, that we used when we had a kitten and tried introducing her to our old kitty Meow. That thing worked wonders! I know with my mom and dad's male cat Butch, he sprays plastic bags and he really liked my backpack when I was in school, but only if I left it by the door. (I learned really quick to take it to my room right away. ) We put the feliway (spelled that wrong....) plug in by the front door and he hasn't sprayed anything in that room for over 5 years. They stopped using the plug in 4 years ago. Hopefully having more will calm his spraying urge!