You need to define the direction the ball actually starts in order to have a cure suggested as the cure is different for each....
the ball starts to the right, straight or to the left?
With hooks you can as suggested keep opening the face bit by bit, unless it's already starting to the right in which case you need to straighten out your swingpath and leave the clubface where it is. (sponge drill is then NOT the way to go as you're already too far in-to-out).
