ADVICE : don’t let anyone sell you a wooden nutmeg

 
don’t let anyone sell you a wooden nutmeg This bit of advice to the unwary to be on the lookout for fraudulent sales schemes derives from the 19th-century practice of selling imitation nutmegs made of wood.

A Yankee mixes a certain number of wooden nutmegs, which cost him 1-4 cents apiece, with a quantity of real nutmegs, worth 4 cents apiece, and sells the whole assortment for $44; and gains $3.75 by the fraud (Hill, Elements of Algebra, 1859)

This practice was supposedly prevalent in Connecticut, “The Nutmeg State,” although whether the sellers were itinerant peddlers or natives of Connecticut is debatable.
don’t take any wooden nickels According to Wentworth and Flexner (Dictionary of American Slang), an Americanism equivalent to “Good-bye, take care, protect yourself from trouble.” A wooden nickel is a wooden disc or souvenir which costs a nickel but has no legal value. The exhortation may have originated as a reminder not to be duped into buying such a worthless thing. Popular in the early 1900s, don’t take any wooden nickels is less frequently heard today.

In the mean wile [sic]—until we meet again—don’t take no wood nickels and don’t get impatient and be a good girlie and save up your loving for me. (Ring W. Lardner, The Real Dope, 1919)