"If you don't put on your slippers, your toes will fall off and then you won't be able to walk like everybody else!"
Sometimes the old-world spook stories work.
I wouldn't recommend getting wrong things into their heads, because you (or someone else) will eventually have to teach them that it was not true, or they will discover it themselves, and that will undermine trust in the other things you said.
I wouldn't recommend getting wrong things into their heads, because you (or someone else) will eventually have to teach them that it was not true, or they will discover it themselves, and that will undermine trust in the other things you said.