HIT OR DIE!!
That's what I call my latest drill to catch their interest before they know what it's all about. Ever get tired of telling the hitter he needs to stay back and wait in order to hit the outside pitch? When they go the "other way" the whole swing changes, they loose their hips or twist their torso to inside out the ball?) and watch for proper reaction. Repeat this drill until the hitter's natural reaction is to turn away. Good Luck!
TRY THIS: Turn the hitter sideways in the tunnel as if you were to do flip ups into the net right in front of him. Now stand directly to the side of him so that you are facing directly at his chest. Give him a few soft tosses right at him and make keep his same swing. After a couple now back off to about twenty/twenty-five feet and pitch overhanded directly at his belt buckle. Obviously, you are not throwing your hardest, but keep the speed up so the ball isn't arcing, a moderate pitch. Now when he strides, he must keep his hands back or the ball hits him. I'm not nuts guys, believe me, they hit the ball AND they stay back.
They can now say they survived HIT OR DIE!
Remember, when a batter has a good swing, any kind of hitting drill is good for him. Variety is the spice of life doing drills also.