If you want an explanation for why he would try ivermectin for cancer treatment he had a lot of beliefs in that vein for a long time. I consider that tragic for him.
James Hoffman, the coffee YouTuber, had an interesting comment on how he tried to use that in one of his 90s barista competitions, but seemed skeptical of it now. Scott remained a believer.
Tl; dr: it's about adding a second layer to your communication which attends to the subconscious, not unlike art. It was originally for therapy, but unfortunately a lot of businessdorks in the 90s got into it and perverted it.
The Secret has sold 30 million copies.
And at the end of the day, it's prayer. 'Prayer helps, somehow' is a very common worldview.
He said after many years he wasn’t sure what hypnotism was exactly, or even if it was an identifiable thing at all, and that in a lot of ways he was just giving people license and cover to do stuff they probably wanted to do anyway. You can’t hypnotise people to do something they don’t want to, apparently.
So if he says “Come up on stage and cluck around like a chicken, make a real show of yourself in front of the crowd”, then quite a few people will go and do it and come away saying “That wasn’t me, the hypnotist made me do it, but what laugh eh?”.
He was less sure how this might apply to (for example) hypnotic pain control, but it was an interesting take.