Émile Coué genuinely seems to have wanted to help people by teaching them how to plant helpful directives in their subconscious minds. Whether he was effective is something that's still debated.
Research:

Sara Weiss’s Journeys to the Planet Mars
39:45

SYMHC Classics: Charles Colchester
33:49

Behind the Scenes Minis: Lager, Ale, Emo Girl
25:06