Ofcourse they don't work. If they did work why would anybody tell you about them?. The fact that they use thier time to tell you about them rather than trading and making money means that they do not work.
I've also heard on that podcast a good explanation for why traders bother selling courses even if they're good at their jobs. Trading is volatile, so you want to acquire alternative income streams. I think that's a point that any entrepreneur would find reasonable.