The reason the body gets the club moving in an outside-in motion is because the golfer isn’t getting enough hip and shoulder turn. When a golfer loses depth, the lack of inward hand movement from beginning to top of the swing, they’re starting from a position that can cause a slice. Unless, the golfer reroutes the club like, Matthew Wolff & Jim Furyk, it would be difficult to get the club moving on an inside-out path. The best drill is one where you have a mirror on your trail side and watch the hands go through your trail bicep on the way back and the way down. One other position you should check would be when the club is parallel to the ground, make sure the club head on slightly inside your hands. This will insure an increase shoulder/hip turn.more neutral/positive club path and increase shoulder/hip turn.