Really!! Well I know it may sound foreign to you but in fact MANY children are brainwashed by their parents to follow and adhere to a specific religion. I can definitely give you proof of this if required and in addition show scripture from holy texts that encourage this type of brainwashing!
Children can't be "brainwashed", because there's nothing in their brains to be washed.
You're talking about indoctrination, which is impossible to avoid no matter how hard you try.