Ah, I love a debate where the one being attacked refuses to play because in reality there may not be a defense. You find this with churches that have an entrance fee.
But I will help. Really! The fact is that there is truth in Dianetics. A simple fact is that words are powerful. At times, we hear things and our brain rewires. Dianetics is a great book to learn this, but so are a thousand other books and a local psychologist.
Here is the funny thing, this principal, that we can be influenced by others, has been known a long time. Hubbard just put a pretty wrapper on it at the height of the self-help revolution. Everything else is perhaps greed and power mongering.
Words and events do change us. But so do the words of any organization that promises to fix that and change you for the better. People are addicted to psychologists, lovers, friends, and even charitable organizations too. Some via the words that change their minds to think they need them, or just as simply, self talk.
To be a skeptic is to question all we hear. Words change us, so it is best to not just believe what we hear, especially when there is a fee/donation/offering or other sacrifices are required. I learned that from Dianetics.