William Camilleri by all accounts does have skills of clairvoyance. In practice he exploits this talent, to convince his followers to seek his advice on everything.
Look these up:
Dr Fox Effect
Barnum Effect (aka Forer Effect)
"The Barnum or Forer effect is the tendency for people to judge that general, universally valid statements about personality are actually specific descriptions of their own personalities. A "universally valid" statement is one that is true of everyone—or, more likely, nearly everyone. It is not known why people tend to make such misjudgments, but the effect has been experimentally reproduced.
And stay off the phone with them, as stated. There are other threads here showing their phone techniques.
Any time you see an ad, dont even read the content. I will explain why, in a moment.
Instead, find the phone number and plug it into Google and see what that phone number is attached to.
You will be surprised.
Now here is why I advise reading the phone number first, and not reading the content first.
A classic ad will consist of a series of questions.
Most normal persons will answer 'Yes' 'Yes' 'Yes' 'Yes' 'Yes'
That is an example of a trance induction 'yes set' and will put you into a light trance.
Please dont kid yourself that you are too smart or have a Ph.D or MD and wont fall for it.
Trance induction bypasses the part of us that gets the degrees and generates IQ scores.
If you dont go to Google and check the telephone number, and instead, read the questions, go yes, yes yes, and actually phone the ad, you're already on toast.