It is known and widely acknowledged that the Church of Scientology and its members are against drugs. Drug use or abuse is not something that the Church is accused of.
Torture is against the law in most (if not all) countries, certainly in the US, and if the Church of Scientology was on trial for torture, I'm sure it would be front page news.
Psychological-Stress techniques would include restraint, food and sleep deprivation, use of images and/or noise in combination with increasing doses of physical pain. (e.g. A Clockwork Orange)
Another term for brainwashing is "coercive persuasion", however in 1987, members of the APA (American Psychological Association) and ASA (American Sociological Association) stated in a briefing to the Supreme Court of California that the "theory of coercive persuasion ... is not accepted in the scientific community" and that the methodology of advocates of this theory are "repudiated by the scientific community".
There is a document written on Brainwashing. It was not written by the Church of Scientology (though a church did print copies and distribute it in 1955 to get it known what was happening). It addressed pain-drug-hypnosis and psychopolitics. It is true cold-war commie infiltration stuff. If you don't think it's in use today, look around... made up mental illnesses with no cures and non-stop drugging. Drugs to alter drugs. Drugs to come off drugs. Drugs to mask the pain. Drugs as band-aids. Drugs used as preventative measures in the case someone might be depressed about something. Unauthorized drugging. Remember when we "said no to drugs"? We don't anymore. Because we have "chemical imbalances" and energetic kids who would rather run around than learn subtraction have ADD or ADHD. But now... millions of people are slaves to their "medication". Medication (drugs) which are not even addressing the problem, if there is a problem that actually really exists. That, my friends, is pain-drug-hypnosis.
Brainwashing techniques are used in deprogramming, which is using these techniques to "break the faith" of a person away from their religion. Deprogramming is not just attempted on Scientologists, but on parishioners of many religions, especially smaller or newer religions.
L. Ron Hubbard compared brainwashing as a type of hypnotism and wrote of this in Science of Survival, a book which predates the founding of Scientology.
“There is another form of hypnotism ... This form of hypnotism has been a carefully guarded secret of certain military and intelligence organizations. It is a vicious war weapon and may be of considerably more use in conquering a society than the atomic bomb. This is no exaggeration. The extensiveness of the use of this form of hypnotism in espionage work is so wide today that it is long past the time when people should have become alarmed about it. It required Dianetics processing to uncover pain-drug-hypnosis. Otherwise, pain-drug-hypnosis was out of sight, unsuspected, and unknown.” (L. Ron Hubbard, 1951)
Years after Hubbard learned of and exposed these government-sponsored psychiatric mind control experiments, documents released under the Freedom of Information Act detailed the extent to which these techniques were being usedmany of them on unwitting citizens. Release of these documents also resulted in Congressional investigations and actions to ensure necessary safeguards were established to prevent the recurrence of such abuses.
CIA Brainwashing Article 1
CIA Brainwashing Article 2
CIA Brainwashing Article 3