That's it elk,get him even more confused than he already is.
I have heard of it but never done it.
I think he needs to stay away from the 60 yard stuff right now but he could do the same thing at 30 or 40.
Walk back should start at 20.You can then shoot at 10 yards Using the 20 yard pin.Then repeat at 30 yards and still use the 20 yard pin.If you are confident and comfortable with 40,then do the same there.If the arrows hit to the left,as you increase the distance,move the rest right.Or the opposite if they are hitting to the right.Do this untill you get a vertical drop.
I like to put a piece of tape on the target,use a plum to make sure the tape is perfectly straight up and down.
I will shoot for groups after thiscomplete.You can read about this method in my link.