You can find this exercise on page 194 of the book Synergistic Golf.
Exercise Type: HEAVY BALL
Exercise Category: FLEXIBILITY, HIPS, LOW BACK, SHOULDERS
Stand with feet hip distance apart holding ball straight overhead in both hands. Inhale bending to the right side and shifting hips to the left. When you've reached maximum side bend, balance ball in right hand. Continue lowering ball down toward right leg and lengthen left hand toward sky for extra stretch. Exhale pushing right arm and ball back up to meet left hand returning to standing position. Repeat alternating sides 10x.