Im afraid I can't give you a firm answer to these questions, but I suspect that the severity of symptoms will vary between individuals and will also relate, in part, to how often the nasal passages are exposed to such vapours.In tobacco smokers (not via the nasal route) who get a rhinitis due to the tobacco smoke often find that stopping smoking can help ease the nasal symptoms somewhat. I think if your nasal cavities tend to get blocked anyway, then your Mozambique technique is not going to do you any favours.