If you haven't tried them -- and the budget will stretch -- our cat-vet says that some cats do respond to those "plug it in the wall" pheromone diffuser thingies. (Don't plug them in under anything that you don't want humidified.)

They haven't done much for our cats -- introducing a new kitten (well, teencat) actually did better -- but it varies and all. (It would help if Flicker didn't think that running up at other cats was a win-win situation: either they freak out and she's successfully bullied them, or else they will run and she can chase and then they turn around and chase and she runs. *SIGH*)

Good luck!