I can't believe no one has any ideas..!
My bully's breath stinks too. Did you ever try using one of those rubber "tooth brushes" you put on your finger? Mine has good teeth too but I try to use it once a day to get the "yuck" out and clean his one or two teeth that tend to be the source of the build up that can stink.
Also, I would talk to your vet next time you're there to see if he has any suggestions.