Honestly, in all my research, I have not ever heard that a bird who is a carrier can ever shed that designation. I do not want you going on incorrect information here. I am not a vet, certainly, but you want facts, not just to grab hold of something because it sounds more promising. maymie, I'd like to know where you get the information that a carrier can become not a carrier with special care. That's a new one on me. Not saying it isn't true, but can you provide any documentation, testing results of birds who were carriers then were not later, etc. Just doesn't sound plausible to me. I agree that with proper care, a carrier bird may never come down with symptoms again (no stress), but to kick the carrier status, I just dont think so.
As far as VetRx, it is not an antibiotic. It has its uses, but cant cure anything, except maybe to suffocate leg mites, but even mineral oil can do that. It's just Vicks Vaporub for chickens to relieve symptoms, to be clear about it.