There is many ways to clean your lungs after smoking · You can easily clean your lungs by Begin a physical exercise routine. · Perform breathing exercises.From What Happens When You Quit Smoking? It may take 10 years, but if you quit, eventually ... Quora User, Chemistry and Nutrition at MIT, physician. Written Dec 8, 2015. 10-15 years....A long time unless you have permanent damage. 142 Views. More ...