There’s a Yiddish expression to describe something that has no value: “an etrog after Sukkot.” Considering that an etrog can cost $30 or more before Sukkot—the holiday in which this citrus fruit is ritually important—and yet seems to be worth nothing once the holiday ends, it’s an apt expression.
So, what can you do with an etrog after Sukkot? It would be wasteful as well as disrespectful to simply toss this exotic fruit in the garbage—especially when there are, in fact, many uses for it.