Can it not be an open (within reason) discussion? I don't think men can be expected to turn a blind eye to the subject in general, even if most do anyway.
Personally if i was a dad to a daughter i'd want to know about the dangers of toxic shock etc.
Re menstrual cycles, is it not right though that sometimes when women are in a group for whatever reason they can synchronise (due to all the hormones and pheromones kicking about the place)? I've also heard that pregnant women can be affected by the gravitational pull of the moon, so maybe these two things are being confused in some way to produce the misnomer. Or maybe all of that is BS!