Lulu, i also hate the smoke hoods...but during the smoke filled cabin exercise it is not real smoke. it is the theatrical smoke they use in the theatres, so even if you did not have a smoke hood on you could breathe. i am pretty sure this is the same for every airline (correct me if i'm wrong!!). also, at our airlines, the smoke hoods we use in training are duds. there is no oxygen in them, therefore you breathe by little holes in the neck.
it is terrifying, if you don't like confined spaces like myself. however, it is all in the head. and if you prepare yourself mentally for the exercise then you will be fine.
of course, if you ever had ot use them onboard, i'm sure adrenalin would kick in and you wouldnt even think about it.