Maybe something along the lines of "Are you going nuts? Check out AGD" and a squirrel - but if the majority of students don't understand Greeks they might misinterpret it and think you're some sort of mental health service.
Or consider this: Back in the 20s and 30s when "nice women" were first starting to use cosmetics, the magazine ads were often very text-heavy and instructional - so the women would know what the products did, the effect they were supposed to create and how to use them. The ads were often literally their first exposure so they were pretty remedial. You might want to do something similar.