You can wash Mullein and dry with cloth or paper towel. I dry it outside in the sun under a light cloth. I make a strong tea and drink daily (with honey and sometimes lemon). Also make a tincture by filling a jar with dried leaves and cover with the highest proof vodka I can find letting it sit for 8 weeks. Then strain and put liquid into dropper bottles. 1 dropper full per day. Also make apple cider tincture (for children). Make sure you turn jars top to bottom from time to time. Have found this works well, helps reduce mucus, coughing and clears sinuses. Several requests for more from those who use it regularly. I would not even suggest it would cure MAC or other lung ailments but it has helped with mucus reduction in our case.