If you're looking for positive examples, there are many.
Look up Paul Haggis, Mike Rinder, Jason Beghe, Leah Remini from scientology. Fully recovered. They're on youtube. (https://www.youtube.com/watch?v=KHb0BZyF5Ok it's long, but worth it)
If you search the net, most ex-cult and those who left extremist religions are going through many issues, but are fully recovered in terms of never falling for a cult again and realizing a certain kind of wisdom from it.
There is no specific answer on how to reverse or counteract brainwashing. No one has that answer either, not even the pros.
Some people cannot be helped.
Some people have to be left to their own devices, they will come out themselves.
Some people can definitely be helped.
It is up to you to decide whether it is worth the effort.
Look up Paul Haggis, Mike Rinder, Jason Beghe, Leah Remini from scientology. Fully recovered. They're on youtube. (https://www.youtube.com/watch?v=KHb0BZyF5Ok it's long, but worth it)
If you search the net, most ex-cult and those who left extremist religions are going through many issues, but are fully recovered in terms of never falling for a cult again and realizing a certain kind of wisdom from it.
There is no specific answer on how to reverse or counteract brainwashing. No one has that answer either, not even the pros.
Some people cannot be helped.
Some people have to be left to their own devices, they will come out themselves.
Some people can definitely be helped.
It is up to you to decide whether it is worth the effort.