Scientology is based on a bunch of low-level hacks on human perceptual routines and cognitive biases. (The staring one works on others by intimidation, as you look confident in an odd therefore unpredictable manner; the routine itself trains you to uncritically accept what's in the later, sillier material.) Hubbard did rather well for someone with no theory and only an aim (money and fame) in mind. I would, however, caution that there are few arts of mind-hacking that are darker.

The other major hack going on in all of those routines is people paying attention to you. Being paid attention to is an extremely powerful behavior modifier, and it's a major recruitment tool used by cults of all kinds.

(Not only is staring paying attention, but in the other exercises, the instructor is clearly paying attention to the slightest detail of everything you say or do. This type of attention from parents and teachers tends to stimulate a desire to please the person giving the attention.)