No one commits to the bit like Nathan Fielder. In a 2015 episode of his series Nathan for You, Fielder responded to the discovery that his favorite outerwear brand had published a tribute to a Holocaust denier in one of its catalogs by launching his own brand called Summit Ice, a startup with two goals: producing quality jackets and raising awareness of the Holocaust. The idea, a sendup of the way corporations struggle to link their products to tenuously related causes in the hopes of seeming more altruistic, was outlandish enough. But Fielder wasn’t entirely joking: Summit Ice was a...