Go for it, scare the Hell out of them.
This is our/your time to get even with them, before they turn into Teenie bopping Azzholes. (Then you'll wish you had).
Sure, you'll scar a few of the good ones too, and they'll need therapy for the rest of their lives.
Not to worry though, therapy is the in thing for kids these days anyway. You'll just be making sure their parents are getting a bang for their buck.
Have fun making a few of them wet themselves (parents too). Then call it a night, and rest assured you'll save on the candy expense for next year.