I think it's one of those things we as mothers may have told our kids but never think it will happen to us. Fortunately, I'm something of a germaphobe so it never occurs to me to put them in my mouth LOL
But I might mention as long as we're discussing odd hazards, when my oldest was in 6th grade, a girl in his class was home dining with her parents on spaghetti . . .she slurped the spaghetti as kids often do and sucked a noodle into her windpipe. Tragically, she choked to death . . .so just one more thing to worry about . . .