You can find this exercise on page 251 of the book Synergistic Golf.
Exercise Type: HEAVY BALL
Exercise Category: ABDOMINALS, ARMS - HANDS, BACK, CLUB CONTROL - ACCURACY, LOW BACK, POSTURE, SHOULDERS, STRENGTH
Stand with feet hip distance apart and ball held out chest height with straight arms. Trace a sideways figure 8 in the air 10x one direction maintaining good form. Then repeat 10x the opposite direction.