This is an incredibly long article about Ky Dickens' misinformation riddled podcast, and is worth the read... but here's the meat of it for those who just want to know why "facilitated communication" has been discredited, the results have nothing to do with "telepathy", and Dickens is full of shit.

One of the American facilitators who used the practice in decades past was Janyce Boynton, who was trained to use it in 1992.

I interviewed her over email for my piece on spelling that I did back in October, but the best recollection of her experience comes from a journal article that she published in 2012.

In that article, she documented her facilitating with a student named Betsy Wheaton, whose story was later captured in the Frontline documentary “Prisoners of Silence.”

“I passionately believed that, as a facilitator, I could help one of my students break free from her autistic, nonverbal existence,” she explained in the article.

She began to notice that Wheaton was acting out more than normal and even getting violent. She was horrified when Wheaton confirmed her fears by typing out accusations towards her family. She said they were sexually abusing her.

The accusations also horrified the local community. Wheaton was taken away from her family by the local authorities.

But her family was puzzled by the accusations that she had typed out. They hired a specialist named Dr. Howard Shane of Boston Children’s Hospital to try to debunk the messages Betsy had been writing.

He devised what’s called a “double-blind” exam to test the authenticity of the messages.

Wheaton and her facilitator would be shown a series of objects. When they were shown different objects, we could see if Betsy, with the aid of her facilitator, would type out the picture she saw or the one her facilitator saw.

When Boynton participated in the test, she realized she couldn’t get the answers right when she didn’t see the object that the evaluator showed only to Wheaton. Her faith in the entire process was shattered. She wrote in her journal article:

I felt such devastation, panic, pain, loneliness—a myriad of emotions difficult to put into words. The whole [Facilitated Communication] thing unraveled for me that day, and I did not have an explanation for any of it. Almost immediately, I started rationalizing away the truth. Though it was not true, I went away from the testing telling myself that the situation had been hostile, the evaluator had been hostile, everyone had turned against me. Incredibly, I even tried facilitating with the child in the week or two after the testing, resulting in more outrageous and false allegations. The parents, understandably, asked that I no longer work with the child. I felt tremendous loss.

The Wheatons were reunited and Boynton went from a staunch believer in facilitated communication to an ardent critic.

The test that Shane used became commonplace. In dozens of studies, facilitators and their clients failed it.

Without going into detail, Dickens does mention that there were real scandals with facilitated communication in the 1990s. But she chalks the whole thing up to poor training of facilitators.

“Thanks to these awful cases that really uprooted lives, facilitated communication took the blame, not the facilitators,” she laments in Episode 8.

What Dickens doesn’t tell the audience is that to this day, there has not been one study of facilitated communication that has passed the simple double-blind test devised by Shane.

The reason, say critics, is that facilitated communication works through something called the ideomotor effect, a psychological process where people involuntarily move their bodies in response to their thoughts. The effect could explain not only why facilitators were unwittingly authoring these messages but also how people operate devices like Ouija boards.

This is an important point. In my journey through this world, I found few claims that anyone is using these communication processes cynically. Everyone from therapists and facilitators to parents and loved ones really believe that these techniques help nonverbal individuals authentically communicate.

There is no cynicism required because what the studies of facilitated communication ultimately proved was that the facilitators were subconsciously influencing their clients, just like some people have always believed that Ouija boards or dousing rods work.

And here is the relevant (and pretty conclusive) section of the Wikipedia article:
https://en.wikipedia.org/wiki/Facilitated_communication#Blind_testing

By 2005, more than 50 controlled studies and blind tests had been conducted, in addition to numerous controlled tests conducted in legal cases. The studies consistently showed "without a doubt" that the messages obtained through facilitated communication were controlled by the facilitators and not their communication partners.

The vast majority of evidence now indicates that facilitated communication is not scientifically valid. However, this information has not stopped many individuals from using this technique under various circumstances and furthermore, advocating for its effectiveness. The overwhelming majority of studies conducted on the efficacy of this technique has revealed that any "positive" results indicating that facilitated communication has worked can be attributed to the facilitators themselves. Be it the facilitator attributing their own beliefs and views onto the individual, or creating a pseudo-personality for the disabled individual based on their previous encounters with them, it is clear that the facilitator is really the one doing all the communicating.

The American Psychological Association (APA) issued a statement in 1994 that there was "no scientifically demonstrated support for its efficacy." Finally, even further defining facilitated communication as a pseudoscience, the APA issued a statement indicating that facilitated communication studies have repeatedly demonstrated that it is not a scientifically valid technique and that it is a controversial and unproved communicative procedure with no scientifically demonstrated support for its efficacy.