I have one of those "Inside Approach" gizmo's laying around, (I forgot I had it) and I have been swinging my driver (no ball) with it in my backyard when I get a chance......It seems to force me to swing inside out more with more of a sweeping action.....You have no choice, because it takes just one poor swing and the foam covered arm goes flying. After a couple of bad swings, I never hit the arm again...just grazed it a few times...
I should take it out to the driving range and hit some balls with it, but I admit I would feel funny doing that..I know--- it's silly, but it is what it is....
Anyway, thanks for the tips....I keep on plugging away....and I have been doing better....