You have a customer who gives her name as "Fanny Batter". Is that a permissible name?
What about "Juan Kerr"? Or "Amanda Huggenkiss"?
It's not about replacing "ass" with "butt", but detecting rudeness/humour in context.
I'd be amazed if machine learning can solve this one. It's extremely hard for humans.
* all those names should be rejected btw