Cleansing the lungs from long term cigarette smoke can be tricky and take a while. One thing that really helps to get things moving out of the lungs and also very moistening, which is the opposite of the dry smoke of cigarettes is Steam Ventilation. What I recommend and do as needed for stuck congestion, is this:
Boil a pot of water on the stove. When it comes to a boil, turn off the heat. Bring the pot to a table so you can sit by it. just before the treatment, add some fresh herbs like lavender, rosemary, lemon balm, basically many aromatics work that might be readily available in the garden or market. Dried herbs will work too if that is all that is available. Can also use a few drops of essential oil, like eucapytus, or rosemary, cederwood. Once the herbs are in it, sit in front of the pot with a towel and cover your head and pot with the towel and breath in this steam. Be careful of course, as its hot. Take breaks as needed, treatment can last 20 minutes. It will loosen things up, he might spit up phlemn, so being able to spit somewhere or into something is good. He can do this a few times a week to help to move what is in the lungs. Putting the rub on the chest is good too, you can do this either just before or after, depending on what feels better to him. Also, rubbing the chest with a washcloth, can help to stimulate the lungs as well. Hope this helps
Mary Sheila