I just kicked in a 3rd (and because I'm a mod, binding) close vote for this question:
How do protestant youth group ministers reach apathetic parents of religious education students?
However, I have some sympathies for it. It's highly subjective, but there are good and bad kinds of subjective. It's the kind of things where everybody and their grandmother is going to have an opinion on and want to chip in. At the same time, some experienced voices could bring some clarity to what the issues involved actually are.
I am inclined to think that there are two problems that must be addressed before it could be workable.
It needs to target a tradition. Even if answerers and their experience don't have to be from that tradition, they must at least not run contrary to it. There are plenty of traditions that would see it as inappropriately invasive to even consider that sort of thing, and other that consider it the wrong end of the stick to be evangelizing kids without having reached their parents in the first place.
There needs to be some kind of guideline for what answers are permissible. How would you deal with a flood of parents ranting about how awful it was of you to even want to indoctrinate their children? At what point (other than agreeing or disagreeing with content) do you say an answer belongs or doesn't belong?
If those get addressed somehow, it seems like the kind of subjective question that Parenting.SE deals with successfully but that we haven't yet worked out how we will approach.
Whats the communities take on this? What would it take to make questions of this vein constructive and on-topic? Is there a direction we can send them or is it a lost cause for now?