"do unto others as you would have them do" - you can't teach a child to calmly express their emotions when you are hitting them everytime you get mad.
Didn't Jesus himself say "blessed are children"
I personally refer to spanking as "adult temper tantrums" to illustrate my point - but I doubt that would go over well since you are working at WIC.
But seriously - that is what they are. I can't control you, and can't handle my own emotions and frustration with this situation so WHACK. That is a tantrum to me.
"To gain respect, we need to give respect" - please and thank you go a long way. Kids like to feel respected and like they have some control over a situation.
"Violence begets violence" - screaming, hitting, etc it only teaches your child that these are appropriate ways to react and express emotions - and cause them to do so too.
"Modeling good behavior is the best way to teach your child how to act appropriately" - you want to have your child clean up toys, ask them to help you do it. show them how it is done. You want your kids to treat other children nicely (perhaps not hit/kick/bite/scream/be rude/name call) perhaps you should consider not treating them like that yourself.
"Some kids require transitions, it helps them listen and cooperate if they know exactly what is going on and what is expected of them ahead of time" My DS is like that. He gets 5, 2, and 1 minute, and even count to 10 warnings. Not warnings as in time out/bad behavior warnings - but alerts that a change is coming. Like - Ten more pushes on the swings before we leave the playground. 1 more minute and then we need to clean up. Okay its time to cleanup when I count to 10 - 1, 2, okay you want to do it now, lets do it!
"patience is a virtue we all need to practice - and this is a perfect opportunity!" DS hears that alot. LOL So does DH. Heck, I even say it about myself. It is fast becoming a family motto around here. LOL
Can you put out some literature or books regarding gentle discipline techniques? Even if only one person looks at it in the waiting room - that is one person who may chose to break the cycle of violence.
GL - I saw alot while working in preschool/day care - including parents who actually gave us permission or requested that we spank their child.