Well, what do I know, but it seems to me that what the writer, thinker and Sufi mystical exponent Idries Shah was doing was conducting an innovative (or should I say relatively unknown?) experiment in long-distance learning, knowing that most would have no physical contact with a Teacher, knowing that most would not convert to Islam. To re-hash what I've written about in the past, I think that working with the materials (both didactic materials and the teaching stories, which some ignore) works on the commanding self and delinquent or depraved nafs, and the self-accusatory nafs. And I sense that there is then sporadic, but increasingly reliable, activation of the inspired nafs.
However, there comes a point when looking back on the depraved nafs and self-accusatory nafs becomes counter-productive. Even at the stage of the inspired nafs, there is an element of pride involved in what one sees as ones own accomplishments, when in reality these are things which one is gifted. There needs to be a turn around.
The question is (and I think this is a gamble that Shah took) is whether working with the materials, and on ones self is sufficient to induce a self-sustaining reaction and open up the heart, the heart and other lataif, (latent organs of subtle perception), and allow one to come in contact with, and work with, something outside ones limited self; an inner guide, if you like, with whom one may engage in inner dialogue (and here there is common ground with Western esoterica, contemporary depth psychology (eg active imagination), and illuminationism (eg imaginal world, 'al am al-mithal)).