Oh boy, trying to get the pitcher at the lower levels to recognize that the umpire puts the ball in play is another issue. I did CYO (7th and 8th graders) last week as a favor to someone and it took at least 3-5 times before the pitcher really knew that I was putting the ball in play. I finally started explaining it when a new pitcher came on the mound.
BTW, that wasn't coaching, it was preventitive umpiring. The kids were trying pick-offs with the time-out. That gets the parents going more than the kids.