Skycatcher,
The Mueller-Beggs spin recovery method gets a mention in CAAP 155-1(0) Aerobatics. It does however have a number of disclaimers including the fact that it will not work in many types of aircraft.
7.24.5 The procedure is mentioned in this CAAP for information purposes. It is NOT being recommended as a spin recovery procedure. However it may possibly be useful if a pilot becomes disoriented.
Mueller-Beggs Spin Recovery:
• Close throttle;
• Let go of the control column;
• Full rudder opposite to rotation (yaw);
• When rotation stops - centralise rudder;
• Re-grasp control column, roll wings level and recover to level flight.