It is generally taken that if I tell you a joke, then have it explain why it's funny - it's not probably not funny.
I continually return to one of my own short pieces. If I submit it I believe it will be viewed as a 'nice' , 'pretty' piece of literary fiction. But I also believe it is extremely clever. But if I have to explain it . . . maybe not so much?
I've had to edit this because I sent you guys way off base. I'm only talking about flash fiction. It's rooted into the culture of story-telling (verbal vs written). A deal of comedy is rooted in misunderstandings, particularly the audio aspect of dialogue. Ergo, it doesn't matter how it's spelt the recipient hears the same word.
e.g. A woman goes for a job interview.
"Wait," says the receptionist, busy filling a form. "You can't ask me that!" objects the woman. "Okay . . . so I put on a few pounds over Christmas but . . ."
Expanding this theme, I wrote a short piece in which the true meaning only becomes apparent when it is read aloud.