I've been an asthmatic for 40 something years & was a smoker for around 20 years (around 20 a day). It's 5 years now since I had my last cigarette.
I can honestly say that over the years, smoking has never made much difference as to whether my asthma was better or worse. Being amongst smokers doesn't bother my lungs either. At the moment my asthma is pretty well controlled with just Advair 250 but it's been far worse at times since I stopped smoking, no different to when I was a smoker.
I was really disappointed when I stopped smoking because I didn't smell things better or taste things better, like all the leaflets tell you & while my lungs cleared themselves out, there were times I felt I must've coughed up half a lung. The memory of that alone is enough to put me off ever smoking again
I'd say that in the long run, I've probably done myself & my lungs a huge favour by not polluting them. I think though, if I'd found that smoking made my asthma worse I'd have given up years before. I once spoke to a doctor who told me that smoking a couple of cigarettes a day probably wasn't a bad thing as it irritated the airways & kept them open. Strange thing to hear a doctor saying that. I was also told by a doctor that I should get rid of a pet bird because it was causing my asthma. I did that & it made not a blind bit of difference.
In the past I've smoked hash & found that acted as a good bronchodilator. Doctors have agreed with me but at the moment it's only being experimented with in some of our hospitals as an analgesic - shame