@rebecross Wow! You led me down another rabbit hole with this question!
I went reading, and learned that there is ongoing research on the topic.
It appears, possibly, that hyaluronic acid (HA) helps thin and liquify mucus - some research has been done on both oral and inhaled versions for people with Cystic Fibrosis and certain types of asthma or bronchospasm.
Here is one article I found:
https://pubmed.ncbi.nlm.nih.gov/33003557/
So perhaps your pulmo is on to something - maybe the combination of HA and saline was liquifying the mucus too much?
Can't wait to hear what you learn next.
Sue
I can't