Rationale for smoking cigarettes while working in the lab- hydrogen cyanide can combine with tobacco to produce a foul smelling compound that can be an early warning for cyanide exposure.
Drawbacks- a dozen other things can combine with cigarettes and explode.
But who cares. We always plan for the worst and hope for the best, don't we? Must rush and remind my experimentalist friends of this fact. As for me, I can generate as much CN- as I want and be blissfully safe from it...
Update: My cigarette loving friend from Mexico has just admitted that he does not see much of an advantage in saving himself from cyanide poisoning, at the risk of dying from lung cancer or third degree burns. He would rather not smoke cigarettes near his apparatus. People are getting wiser. I am happy.