From a quick search: “A Schlemiel is an inept clumsy person and a Schlimazel is a very unlucky person. There’s a Yiddish saying that translates to a funny way of explaining them both. A schlemiel is somebody who often spills his soup and a schlimazel is the person it lands on.”So the “Hasenpfeffer Incorporated” mentioned, adds to the L&S ditty, meaning you have the last ingredient (the soup) to the humorous situation being alluded to.
Yes, I should have commented under DirtyDragon’s post. I was absolutely trying to reference Laverne and Shirley.