I had given up smokes for about 3 years and found I still coughed occasionally. It wasn't a big cough more just a throat clearing but always 2 or 3 in a row.
That left me after about 6 months of not smoking.
I didn't get the cough up all the muck type coughs that i have seen others get around me when quitting.
I've only been vaping for a month or so, because slowly but surely I was picking up the fags again and this is to stop me from doing that.
I have found, vaping also produces the same cough in me. ( I don't use nic)
TBH I think it is a little psychosomatic and that i don't really need to, but it's what I did for 20 years odd.
Old habits die hard I guess even if you think they're gone.
..... if you did anything 30+ times a day for 20 years the muscle memory would be excellent and you would be ..... HOT at it.
Oh the time we have wasted
There's only one other thing I've done every day for over 20 years but let's not talk about that

.......although my technique here is excellent