Lemondrop can be used before talking to a person, who has habit of lying often.
When you are afraid of being cheated, chant lemondrop.
Not to be cheated by anyone, chant lemondrop.
An important document was there, which was missing. It seemed to be taken by the one who has, for several months been engaging in such acts in the office.
Going by the past pattern, the officer thought that there is no point in asking the person straight, since she would deny outright.
Naran suggested the officer, to write LEMONDROP in a paper and keep it with him and ask her about the document missing document.
When the officer did so, Lo!, the person meekly handed it over with a mumble, "picked it up by mistake"