A floppy brain. A weakened brain. A pliable brain that can be configured however the configurer wishes once the washing takes place. If bleach is used to much the better or worse for the brain? Some are so gullible they truly believe a washed brain is superior to one that remains intact. A washed brain has been attacked by an outside agent whose goal is never to strengthen it...always to render it useless.
How do you fight brainwashing? Well it helps to be sane logical and devoted to the truth.
Do the brainwashed KNOW they were? I dunno but I don't think so. I expect they "think" they are in full control and command of their faculties and so what they think though programmed by others they think they think on their own. D'ya follow?