An old herbal treatment for the lungs is inhaling the fumes of apple brandy from a charred oak keg. Ethanol is an antiseptic, while the apple and oak flavoring compounds help stimulate the lungs to repair themselves.
Since I've started huffing on apple brandy, the itch in my lungs is much better than it used to be.
The charred oak keg is important, because it facilitates the evaporation of the brandy into fumes. Someone shared that they use oak spirals in a glass container: https://www.facebook.com/EdgarCayceOnPsychicHealth/posts/pfb...
My mom's husband tested positive for the virus recently. She developed a cough, but 'tested negative' (home tests are probably mostly worthless). After a month she was still coughing. I set her up with a barrel and sent her husband to the liquor store for apple brandy. Her cough was mostly cleared up in a week. Then she got sick again, but this cleared up quicker than her September case of "not-coronavirus".
edit: treating lungs with inhaled alcohol is science-approved: https://news.ycombinator.com/item?id=22756511