I just saw an interview with an Italian physician where he briefly mentioned therapies for the lung before things got to the stage where ventilators were needed: https://youtu.be/3dmIzW3icRs

It was a brief reference without enough details to be sure that he was referring to clearance methods similar to our the same as what you reference, but it sounds as if this may be part of therapy already. So well in line with what you have described.