About 20 years ago the FAA issued a bulletin or alert to flight instructors about spin and recovery characteristics of Cessnas. The same information was in Flight International magazine of October 1978.
Some extracts relevant to recent posts on Cessna 150/152 here:
“…. Some pilots of modern aeroplanes say that ‘if you let go of everything, it’ll come out on its own.’ Using some spectacular film and figures, he showed the result of doing this in ... the 152. …
… company’s recommended recovery technique …
(1) Check that ailerons are central and throttle is in idle position.
(2) Apply and hold full rudder, opposite to the direction of rotation.
(3) Just after the rudder reaches the stop, move the control wheel briskly forward far enough to break the stall.
(… full down elevator may be required at aft c.g. loadings.)
(4) Hold these control inputs until rotation stops. …
The same information is in Kershner's book, The Basic Aerobatic Manual - essential reading for anyone instructing spins and/or aerobatics in the Cessna.
Beggs confirmed Kershner's tests of the Beggs-Mueller method on the Cessna 150 - it doesn't work in some spin modes to the left. Refer his article in the October 1985 issue of Sport Aerobatics and his comments on the above method - full forward yoke used in that spin where Beggs-Mueller doesn't work.
It’s a lot easier these days to obtain factual information (as well as rubbish) on the internet. Happy to send more details in pdf to anyone.