Sending a "Message"

Do any of you, who do walk through's or otherwise interact with your audience, make a point of giving your TOT's a message during your spiel? I always drop a message saying how "Halloween is a time to remind ourselves that there IS Evil in the World". If the group is adolescents, I mention staying away from drugs; smaller kids get a "Never, ever talk to strangers" message. Over the years I've seen numerous parents in the crowd nod in agreement. And even the cops! We sometimes get patrolmen coming through to make sure there are no "issues" like crowding or Fire Code violations. (Don't BS me, you just wanna see the show!) and the cops think it's a great idea. When kids are scared or nervous, they hang on your every word, you have REALLY got their attention. And it actually serves to set up the last, best scare of the night. You start lecturing the kids, they figure the show is over, they let their guard down. And then a strobe light comes on and a maniac with a chainsaw jumps out from behind a curtain.
Does anyone else purposely use this tactic?