There are two opposing effects of "devil's advocacy":

• a negative effect that you point: it makes you good at becoming a "clever arguer", good at rationalizing any position, and does not substitute for genuine open-minded curiosity, as Eliezer argues.

• a positive effect: for high-profile, genuinely controversial in society issues that raise emotional reactions, like the ones Sanchez discusses, the practice of devil advocacy can make you less prone to mind-killing, better at seeing that (two quote two LW memes) your enemies are not intrinsically evil and policy debates are not one-sided.

I think the benefit from the second effect outweighs the harm of the first one. But anyway, I think the main feature of the course Sanchez imagines is to force students to engage with "offensive" viewpoints in a cool, intellectual way, to reduce their propensity for mind-killing reactions. The specific mechanism of making them actively argue for the offensive viewpoints is not essential and could be easily modified.