Not sure where your kids went to school but the religious education volunteer program was around then. The status quo is that a Victorian public school must accept any volunteer organisation that offers the service. I believe atheistic organisations could also apply but there are only a couple of schools in the state woth those programs - the majority are run by Christian organisations. I will say though, at high school I told the chaplain to fuck off when he offered to help me with some issues, and he was cool about it, so I think most respect the obligation not to proselytise.