It was my ID doctor (Winthrop at OHSU) who suggested this, but I don't have as much success with it as Irene does. I get the most sputum while and just after nebulizing, then more with the Aerobika while sitting, sometimes a tiny bit more on my back, rarely anything on my sides. As you say, each of us is different. I do the nebulizing and upright Areobika daily, usually twice a day, and still try to do the whole "set" a few times a week as I want to give my body the best chance to control these bugs.
Anna