For a couple of years my dad (77 years old) has had a dry cough that starts as a tickle then just progresses. He can’t talk for several minutes because he is coughing. No mucus comes up from the coughing. He has seen many docs, had many tests & tried different therapies-acupuncture, cough drops, various teas, etc. those items have all been commercial- not the good stuff- fresh or potent dried herbs, teas or tinctures. No one has really given him any diagnosis or relief. He still has no relief but may have a diagnosis of the pulmonary fibrosis. He used to smoke in his younger days & was in the navy on a ship for 2 years out of high school. Hoping someone has some experience with this issue! Thank you.