As it happens, I got this demonstrated to me a few days ago as part of the FIC. Just for interest purposes of course....
Aircraft C152
Carb Heat ON
Throttle IDLE
Full Flap
Trim Full up
Aircraft enters a stable 15degish left hand descent with minimimal pitch oscillation. Hand and feet of the controls we descended from 5500 to approx 2000ft in reasonably choppy VMC with the attitude never reaching anything excessive.
An interesting demonstration but I am not sure about the practical aspects as discussed already.