Me Myself
Back to my username
Actually, if you want to get all technical about it, then teaching anything to children (whether religious teaching or teaching kids how to read) can't possibly be brainwashing. The whole point of "washing" in "brainwashing" is the idea that information that was there is removed so that a person can be "programmed" anew. Whether it is cult indoctrination, some CIA experiments, extreme government propaganda, etc., the goal is always the same: take someone's way of thinking and change it to fit a new purpose. You "wash" the mind of old ideas to put new ones in. You can't brainwash children as you are teaching them their initial frameworks, not exchanging old for new. Indoctrination, yes. Brainwashing, no.
It may seem pretty trivial, but the distinction is important (IMO) for precisely the reason you state: any and all teaching of children would be brainwashing if we ignore the distinction.
That is what I said earlier too when I sted the actual definition of brainwashing.