Stealth figuring out how to leave the dream world

“I’m still not entirely clear how we got out of the last one,” said Freedom. “Do we just have to … not believe in the world?”
…
“I believe I have a possible solution,” said Stealth. She walked over to Freedom and gestured him down to her level. She cupped her hand by his ear and whispered for a few moments.
Freedom glanced at her, stared across the room, and then nodded. “Yes, ma’am.”
…
“Smith’s suggestions work in a manner similar to dream states,” said Stealth. “A simple idea is planted in either the conscious or subconscious, and the brain reworks memories to accommodate this idea.”
…
“I believe there is a simple solution,” Stealth said. “There is a common sleep disorder known as a hypnagogic jerk. It is an involuntary muscle twitch. Some biologists believe it may be a holdover from our primate ancestors, similar to the Moro reflex in infants.” She looked at St. George. “I suggested it to you yesterday.”
“You did?”
She took a quick step back. St. George heard someone move behind him. He turned and Freedom slammed a football-sized fist into his head.

Excerpt From Ex-Purgatory, pg 538-539
Peter Clines
https://books.apple.com/us/book/ex-purgatory/id676938479