“Brainwashing” means repetitive indoctrination. It occurs primarily in religious cults, schools, and via mass media—especially television, where agenda-laden lessons are guilefully embedded in “entertainment” and even “news”.
To undo repetitive indoctrination is to begin to think for oneself (rather than automatically accept received doctrines or lessons), to work at developing critical thinking (to consider and evaluate the merits of a given idea), to defend one’s intellectual sovereignty (determination to decide for oneself), and to exercise metacognition (seeing and evaluating a doctrine or lesson in the context of the agenda of its source).
Collectively, I call these “undoing” activities recovery (from a cult experience) or reclaiming one’s mind (from our culture of birth). Another term for reclaiming one’s mind is awakening.
“Deprogramming” is not ideal, because it means forcefully brainwashing a victim in a new direction (an initiative by an outside party) after a brainwashing experience, which absolutely fails because it is not self-directed. Successful recovery must be self-directed, for it is about reasserting one’s will and determination.