Not sure he is sold.
Sized for one Tea Towel or swatch of wallpaper with 4 repeats "A Boiled Egg Is Hard To Beat" is a paraprosdokian. Paraprosdokian is a derivative of a Greek word that means “beyond expectations.” It refers to a sentence with an unexpected shift in meaning accomplished with puns, misdirection, deliberate misunderstandings, and witty juxtaposition for humorous effect. Paraprosdokians are a favorite of comedians who deliver “one-liners,” jokes which require only a single sentence. The comic effect occurs because the reader or listener must reinterpret the first part of the sentence to accommodate the double meaning of the latter part of the sentence. It takes advantage of the fact that one word can have different meanings in different contexts or... We expected one meaning and got another. The unexpected switcharoo makes us laugh.