I'm an unbaptized born in. My position isn't quite the same as yours. I introduced my wife to the cult, then never got baptised myself.
You have to be very careful not to portray yourself to your children as the enemy. They are already well indoctrinated, so announcing yourself to be the Watchtower's predicted agent of Satan will not get you a result that you want. Your best chance of rescuing your children, is while they think you are trustworthy. Don't spoil that chance.