Backstory on the milkshake line; (source )
“The line in the final scene, “I drink your milkshake!”, is paraphrased from a quote by U.S. Senator for New Mexico Albert Fall speaking before a Congressional investigation into the 1920s oil-related Teapot Dome scandal. Anderson was enamoured of the fact that a term like “milkshake” found its way into such official testimony, to explain the complicated technical process of oil drainage to senators.”