Earlier quoted context omitted.
I hope nobody takes your idea seriously. Most people aren't super-spies who can go undercover and save society from a cult. Just go to law enforcement, report it and listen to what they have to say.
There once was a professor doing research on cults who sent out his grad students to secretly embed themselves in various cults and report on them. Not all of them came back.. And now we get learn about why that was a bad idea in the ethics portion of psychology classes! Yay!
Professor sent out the grad students. Some of them didn’t come back (died?).
Those are all the facts. Any pontificating about whether it is Good or Bad is just nonsense.