One of my teachers was also a third rate amateur magician. He would go into classes and perform tricks, pretending to have supernatural abilities. He would invariably get over half believing that at least some of what he did was supernatural, and when he did his act well (which greatly involved the nonsense stated to support the tricks, not simply how well the tricks went) he got more than 90% believing he did supernatural things. Afterwards, he would reveal that it was all tricks, and that nothing was supernatural. Students wanted to know how the tricks were done, but he refused to explain most of them, but would explain one or two of them.
This was not in California, nor even within a 1000 miles of California.
I am convinced that, if done properly, one would typically get over half of a class believing such nonsense, as most people have minds filled with rubbish and are not good at distinguishing between good evidence and foolishness. Indeed, most people seem to reject, on principle
, the idea that one should believe things only when they actually have good or real evidence for the belief.
If your story is right, it is exceedingly depressing that telling the students the truth beforehand did not prevent most of them from believing stupidly. That is enough to drive one to despair of most people.
This is also quite depressing:
... Also it turned out that in efforts to convince the students of the truth... that it was just tricks, what worked best was to actually explain the trick. Just condemning gullibility didn't work.
In the real world, there are always going to be some more tricks to be explained, so that if one needs each and every trick explained in order to not believe like a damned fool, one will believe like a damned fool.