Descriptions of the Aiki-taiso from Rod Kobayashi-Sensei:
3. Kotegaeshi Undo
From a natural stance, look at your left palm as you place your right palm behind it. Hook your last two fingers of your right hand around the base of the left thumb and place your right thumb at the base of the left little finger. The "One" count has both hands dropping together, causing the left wrist to bend and twist naturally. You should feel the stretch through the entire arm.
Release your hand and repeat several times for each hand.