30 years ago, i attended a yeshiva (no longer in existance) that was the first to ban smoking outright. that was for all bochrim, even if over 18.
the yeshiva was held up to redicule.
now many who smoked continued, by hiding it, going off campus
but it did stop many from even taking up the addiction
i do believe that at the least, yeshivas should ban smoking in the dorms and the beis medresh….its just a thought.