It only works once. After that, they’ll know it doesn’t even taste like real crayons.

Fun Fact! It was proposed at one point during WW2 to reward Marines with ice cream in exchange for Japanese prisoners, as the… vicious and war-crime filled fighting had led to a severe lack of ‘surviving’ Japanese soldiers, especially since false surrenders were common amongst Japanese troops.

I don’t remember if it formally went through, but ice cream was widely used as a morale booster in the theatre, down to having specialized barges to make it and keep it cool.