One approach might be to train it on what naughty words look like first, then ignore any future images that match too closely to them. That is what it's supposed to be best at, after all.
When I briefly permitted my utter goober of an inner child to have his way, its top two guesses at the result were "syringe" and "cannon", which...really aren't quite as far off the mark as I'd have expected, I suppose.
(No, I won't try a swastika and report back. Immature as I occasionally permit myself to be, I do have some principle and taste.)
