As to Margaret Singer
Singer wanted to be
employed, and to
seem important in other people's eyes, so she pretended there was some super-powerful super-secret super-sophisticated technology that only people like her could help protect against.
She was a swiz in her own right, a con artist just like Hubbard was, an academic PT Barnum.
As to Hubbard's technique
It's called "hope". It's ancient, the Apostle Paul of Christianity pointing out "you are the prisoners of hope" and having people eagerly accept this role for thousands of years, right up to today.
Hope of something better engages the mind and effort in ways that settling for limited expectations and uncertainty does not. There's no big mystery here to worry worry worry over,



as if LRH had discovered the psychological equivalent of atomic weapons. Hope is powerful, and can be instilled by story telling methods. It's ancient.
And he sure didn't have any big oogey-boogy power when the vast majority of people do one or two Scientology actions then leave permanently, and only a narrow percentage eagerly pursue it to the punchline of the joke.
When never ins, ask "Why did you stay" (putting up with bad treatment, being asked to believe in space opera etc), I have sometimes thought that really, it boils down to hope. I did not stick around for decades myself but probably would have gotten that trapped
if I could have afforded to pay for the trap. I intended to go back when I could afford the trap. Anyway, for those that did stay for decades, it does seem like hope, that keeps there there. That's the simplicity of it.
Beyond that, there is the fact that the hope has been strengthened by 'proof' that hope will be statisfied. People do get benefits IMO. Serious questioning needs to be done about the nature of the benefits and whether a "win" from a session is of more value that the "win" from a cup of coffee or whatever, but the point is the "wins" "prove" that hope is justified and hope(s) will be met with real benefits. It seems from reading what "higher level" ex scientology achievers have said, that as they get higher and higher up the "bridge" they rely more and more on hope, as what is demanded of them vs what benefits they get or can conjure up with rationalization, self deception, self censorship etc becomes more extreme.
To say it was only hope would probably seem too simplistic for the "OTs"
especially since "certainty" and "knowingness" etc were implanted so heavily, and those things would mean it wasn't really 'hope' at all, but thinking that things would get better after they finish this rundown or that rundown would become more and more a matter of hope as they failed to achieve what they wanted. However, in a sense hope might not be so simplistic as the simple little thing used by Huhbbid.
Some of the hope that could be satisfied at Hubbards Hope Candy Store.
I was hoping I could gain the ability to leave my body and perceive things while outside my body.
I was hoping to experience myself as immortal.
I was hoping to overcome x y z ......(fill in any of 1 million things you would like to do without.
I was hoping I could get rich.
I was hoping to gain total freedom ---of course there are unspoken aspects here: Total freedom from suffering, pain, death, physical restrictions.