Experience: I was in a Scientology jazz band (2021)
theguardian.com
theguardian.com
When you go Clear you discover that you are actually just an Operating Thetan I, and you need to pay more money to take the courses to become an Operating Thetan II. Then you learn the real truth: that an alien named Xenu...
https://en.wikipedia.org/wiki/Clear_%28Scientology%29
https://en.wikipedia.org/wiki/Operating_Thetan
https://en.wikipedia.org/wiki/Fishman_Affidavit
https://en.wikipedia.org/wiki/Xenu
... and by then you're willing to do anything to save the world, including torture people by putting them in solitary confinement and starving them.
https://en.wikipedia.org/wiki/Scientology_controversies
That's conditioning.
Some percentage of humans are willing to submit to significant demands from tribal leaders in order to demonstrate their loyalty to the tribe, including wearing tribe colors, displaying tribe emblems and flags, and changing aspects of their life to conform to the tribal leader's statements about what is right and good and proper. Quite a bit of money can be spent on this.
And, at an extreme, some humans go looking for a tribe that promises more, and demands more from them. It's a continuum.
Real achievement takes time to bear fruit, while a sufficiently advanced manipulator can near instantly create emotional feedback loops based in illusion. It's something that happens all over the place all the time - Scientology is an interesting aberration purely because its scaled.
If you want to know more specifically what happens, there are many public accounts from survivors of Scientology and countless other cults (or high control groups - if you prefer).
There is a body of literature. Authors include: Robert Jay Lifton, Steven Hassan, Margaret Singer, Alexandra Stein, Jon Atack.
https://aeon.co/essays/how-cult-leaders-brainwash-followers-...