Stan is absolutely right, I was responsible for a few of those RAF operators manual recoveries during my time at BDN, and a few more since on civil aircraft.
There is not, never has been, and never will be, a common spin recovery to all types. Any QFI who teaches initial spinning, to any method than that given in the POH for that type should, in my opinion, be put against a wall and shot. Slowly !. The correct method is that in the POH, students should know that is where it is, that as pilot in command of any type they should be familiar with it, and that it will not be the same on each type.
Yes, most types will respond to one of two or three standard recoveries, the most well known being close the throttle, put the stick in the middle, apply opposite rudder to the turn, and wait for the recovery.
There is another view of-course, which is that an experienced aerobatic pilot, in a type that they know well, can use different series of actions to give different responses. There is nothing wrong with this, initially at a safe height, and wearing a parachute. But, this sort of thing has absolutely no place in initial spin training.
One other thing, use of power deliberately during a spin puts HUGE cyclic loads on the crankshaft and hub and significantly increases the risk of a subsequent engine failure.
G