How did nebulizing with saline affect you?

I'm interested in knowing more about people's experience with nebulizing with either 3% or 7% saline. What differences do you notice when you compare symptoms before and after starting your regime? My pulmo doc says there's no good research indicating nebulizing is helpful, and believes flutter valve (aerobika) will do more. (I've watched the video presentation on nebulizing someone in this group recommended.) I'm particularly curious about the experience of those who cleared MAC infection and used nebulizing post treatment--and continued to test negative.

I don't have asthma and have never produced much sputum. Since a bronchoscopy in May (showing high levels of infection and some blood) and starting the big 3 five weeks later, I've produced none and almost never cough, never have coughed up blood, etc. Have had BE and MAC for at least 15 years.

Thank you all! This group is very helpful.