Next time you have an appointment with him, ask for more information as to why it is not recommended in your case. As I said it might not be right for your stage of things. Maybe you just do not have enough mucus since you do not have Bronchiectasis and he does not want to irritate your airways. Also if your Pulmo is not familiar enough with MAC then you might try to find a Dr that is more specialized. Does he have other patients that he does prescribe saline for? Or is he just against it in general? I would want to know that if it were me. He probably knows best? The Aerobika is excellent for flutter device. I think it is the best one to use.