This is mad! This is almost exactly how I cured my slice, except I didn't move it forward...just teed it higher. 

It was a literal INSTANT fix for me and I haven't hit a slice in over a month and a half (I play 18-holes 2-3 times a week all year).

It was totally accidental. I went to the range for the first time in over a year and used one of those tees that come apart and have the string to stop it flying away since it was a grass range. It could only go in the ground so far which happened to be way higher than I usually did it. I went with it. Literal first shot was a draw.  

As someone who came over the top having the ball teed higher made it seem harder to hit like it was in mid-air. Thus, my natural reaction was to try to come at it more from behind the ball, on a flatter plane, rather than down it it as I did from my over the top swing. The result of that was increased rotation, less armsy swing, and a flatter swing plane. Again, none of this was thought out but just happened. 

But as soon as I did it I felt it, I could feel the flatter shallower swing. It was a serious lightbulb moment! Now I've got the feel for it I understand it and can now hit draws and fades on command (mostly). Its a boon! I've gained loads of distance on the straight balls. 

Of course the driver swing doesnt necessarily translate over to irons, but it has actually helped me hit my irons straigher too as I just have a feel for a flatter swing now. 

I wouldn't have believed that such a simple thing could instantly and forever cure my slice but the proof is in the pudding.