I am really bad at knowing what is truly racist or who might be offended at any such material.
It isn't because I live in a bubble, I work and socialise with people from all races and cultures and we are all good friends.
I like or dislike people for what they are - not their ethnicity - so this makes me a very poor judge of what might be offensive.
Anywhoo - the gag! (which I would like to include in something I am writing)
A man is being accused of being racist (he is obnoxious and ignorant) - he replies,
I am not racist, I have a black dog!
I wouldn't want it being rejected on this line alone.