The method was to progressively search for a mental borderline state by psychic and physical exertion, and the result was frequently an acting performance characterised by actors shaking uncontrollably, spewing spit and snot and other bodily fluids around them. Some likened the method to brainwashing, or those of religious cults.
Renowned for his sadistic directorial style and numerous instances of reducing acting students or actors he was directing to tears and/or a nervous breakdown, very few people doubt his genius.
Several actors have written books which describe their experiences with him, either as students or actors.