So they even expect these things to be demonstrated in turning flight, with full power until the point of stall...
This reminds me of 'Spinning 2' which we used to do in the RAF - reognise and recover from an incipient spin at any stage of flight. It was simple, really - if it buffets, relax the back pressure and keep the ball in the middle.
I tried one of these full power stalls in a Cherokee 140C yesterday in straight flight; the attitude needed to induce a stall in the clean configuration was quite steep and extremely unlikely ever to be selected inadvertantly. To me it seems a rather pointless and inherently dangerous manoeuvre; if correctly trimmed to an initial climb attitude corresponding to 85mph, the control forces needed to increase pitch until the a/c stalled are not something that any properly trained pilot would ever be likely to use in practice.