The Golden Exercise is one of a series of drills created by Paul Bertholy .  They were brought to national attention in the mid 1960’s in Golf World and then later in 1975 by Golf Magazine. There are many versions on You Tube from people who give their own interpretation.  The following video is the correct way to perform it.

If trying this drill here a few things to remember.  The purpose of the drill is to eliminate  the fat shot and to promote missile like iron shots.. The drill should be done at 1/10 golf swing speed.  The goal is to take a divot past the ball on the target side of line of flight.  The extension position should be held for 10 seconds.   This drill can be used to promote a draw, fade, or a shot with very  little curve when done in the appropriate fashion for any of the afore mentioned flight patterns.  The video shows the the draw position.

Perform the drill in front of a mirror using a short pipe or iron to start to see and feel the proper motion.  If done properly in 10 minute intervals  until 2 or 3 hours  cumulative time are reached there will be a change in the quality of club/ball contact.

There is variation allowed.  But all must stabilize the lower body , contain the upper quadrant of the trail side,  and then release after the forward arm is past the golf ball as shown in the video.