I think I know the name of that expensive little bottle. It's called Feliway and can be bought from your veterinarian. I mentioned in another post that my sister is using it on plants and furniture to keep her cats from digging and clawing. I don't know about whether it will help with the spraying problem, but I'm sure your vet can tell you. It is a small pump sprayer. She brought it with her over Thanksgiving to keep her two cats out of my mother's plants! I would say that it is $35 well spent if it keeps them off of expensive furniture and keeps them from putting dirt all over the carpet.
Hope this helps.