-Quote JB-
“Go back to walking in hand, and get REALLY good at stopping on a straight line. Use the whip in front of you, which means to his inside eye. Work hard on teaching him to move his shoulders away from you - first at arm’s reach, then from farther and farther away. Teach him that “whoa” means “whoa right here right now don’t move your feet”, and THAT automatically means “don’t turn in don’t turn out”” Unquote
While I have no problem with most of that statement," whip to inside eye" is worrisome. A schooling whip to inside shoulder is safe enough, and will get the job done of teaching him to move the shoulder away.
There is still a point in time when the person has to make the decision to send the horse forward on the longe. while using but not over using the whip. This takes timing and coordination, and is not something a first time longer want to be trying on a green horse. As I wrote in this post;
Bad Kicking Habit
Started by FirstTimerHere, Jul. 6, 2019, 02:02
You need a mentor or trainer.