Well, I had to get rid of the flip a couple of years ago. Two things that helped were a drill similar to this one
YouTube - ‪Video Tip #8 'Set Up vs Contact'‬‏
Start with a wedge, but then move onto half shots with the 8 and 6-iron. You can even place a tee in the ground a couple of inches in front of the ball and force yourself to hit the tee after the ball. Another way to force yourself to strike the ball and then ground is to practice 3/4 iron shots in a bunker. If you are a training aid guy, the Tour Striker was helpful to me.
The other thing that helped me was to exaggerate the feel that Mike describes in the Nuke video about either pulling or throwing the shaft
down at the ball. The "throw the ball at the ground" drill is helpful on this one. You get some real intersting stares at the range doing it, but it works.