The problem with your question, it's hypothetical. Why would a healthy person be nebulizing? I am not a "healthy" person, when I started nebulizing my sputum was so thick, I would have to stop several times to huff, to clear my airway before I could continue. It was gross! After several months I wouldn't get any sputum while nebulizing, but when I finished, I was constantly clearing my throat of sputum. due to the irritation from the 7% saline. I'm now under the care of a different doctor for the treatment of MAC. The lab that tested my sputum would comment the sample was excellent to culture.
Great after dinner conversation.