In to out impact v. in to out swing was the first conventional instruction pebble to be removed from my shoe! One the coolest feelings is bridging the gap between follow through and finish. After all the effort is takes to go to both arms straight the finish swivel feels like a well deserved vacation! I try to earn the right to swivel.
This is why I think "hitting" is a great teaching tool. Using #1 Acc going to both arms straight is unmistakable in terms of feel. Whose right arm is straightest at follow through? A hitter or a swinger?