when the above-described method was suggested to me, i, too, rejected it. thought it was "beneath me" and all that....
what i've learned, however, is that a rant does nothing but harm your voice, raise your blood pressure, and destroy the respect your cast had for you.
any production can afford to lose one rehearsal when it means that the remaining ones will run smoothly. think about it - would you rather lose part or all of one rehearsal and make a huge point or would you rather be nickled and dimed to death, losing 5 and 10 minutes over and over and over again.
i had a professor who used this method - no sarcasm at all and absolutely no tolerance for misbehavior. if someone's behavior disrupted class, class stopped. period. then asked permission to continue class when the disruption ended. the message got through.
the other major lesson i learned from him is that rehearsal or class starts on time, no matter what. even if there are only two people in the room - work begins at the appointed time, and nothing is repeated. if someone asked, he would answer (very matter-of-factly) "i'm sorry, but i won't be able to do that".
when i started using these two techniques, suddenly people were on time, prepared and focused on a much more regular basis. also - my blood pressure dropped, general mood elevated, and i haven't had laryngitis even once since.