Don't take any wooden nickels

something that you say when someone leaves, to tell them to be careful and to take good care of themselves Hey guys - have a good trip, and don't take any wooden nickels.

Don't let yourself be cheated. This expression was first heard in the early 20th century. Although there never were any wooden nickels as legal tender, country folk going to a city were likely to be cheated by all manner of ruses, including obviously counterfeit coins. Wooden nickels did exist, however, as bank promotions during and after the Great Depression; the “coins” were redeemable for prizes.