I read Dianetics by L. Ron Hubbard many years ago.
Quite interesting but bullsh*t.
I find it very believable that those who are lost and seeking meaning could get sucked into it, like any religion.
This is why recovering addicts many times become Jesus freaks. They need the structure that religion provides.
I've read John Travolta's account of his joining Scientology and Cruise is about the same. They truly believe it has made them successful in the world of Hollyweird. Maybe it has.
Cruise had a very difficult and disruptive childhood. Many actors come from such backgrounds.