Here is the order in which these were added to my routine, allowing about 1month for each to work.
1) Airway clearance, huff coughing plus Aerobika to vibrate secretions
2) Mucinex LA600 mg time release (guaifenesin only, no other ingredients)
3) 7% saline neb once or twice a day
4) 500mg N-acetylzcysteine twice a day
This is in addition to prescribed inhaler for opening airway, and asthma meds as needed.
I learned about the saline after the other methods, or I would have started it before Mucinex, but my lungs seem to need all of this to stay healthy.

Now I will add my cautionary note, this was all with the agreement of my pulmonologist and has worked for me AFTER 18 months of the big 3 for MAC and 2 months of treatment for Pseudomonas. I was so sick at first that that I doubt my routine would have worked without those meds.

I'll be seeing my pulmonologist next week - we'll see how she thinks I'm doing.

Have you been doing airway clearance?