Various dodgy ways are used when people want to get their kids into a school they believe is particularly good. Going to church, or for that matter mosque or synagogue in an effort to get your child into a school where that helps up the chance of getting in is one.

So of course, as you say, does the practice of buying a house in the catchment area. The difference being that you have to be pretty well off to go down that road. Is that really better?

I think it unlikely that children from a family cynically gaming the system in this way are that likely to be the kind of brainwashed pew fodder you seem to think religious schools turn out. In fact I would have thought that you might even welcome their being part of the school, as a way of diluting the religious ethos.

This kind of thing only happens because some schools have significantly better reputations than others. How far this can be a consequence of having a religious ethos is not clear. Undoubtedly are many very good schools which do not have such an ethos, and some "underperforming" schools which do. .