You can find this exercise on page 130 of the book Synergistic Golf.
Exercise Type: HEAVY BALL
Exercise Category: FLEXIBILITY, HIPS, LOW BACK
Stand with feet slightly wider than hips distance apart holding ball straight over head. Swing ball in large arc from top to bottom through legs and back up again. Bending must start from hips and knees then allow spine to flex forward while being supported with abdominals. Repeat 20x exhaling down and inhaling up.