The most frustrating thing about this, is no matter what you do with it, these pieces of trash can still call it a win, because they do absolutely nothing in good faith from the word go:
-You just let them have it and claim it as their own, calling it out when it pops up and letting it become more and more associated with them over time in the process and all that? Congrats, you're saying they have the power and influence to turn something innocent into something completely messed up. That if they want to take it, it's their's, and that they have their power.
-You ignore them and don't let them have it, they continue to use it to hide in plain sight and gaslight others as to what their intentions are, and hide behind trolling and memes and jokes, and just reveling in the ambiguity of it all and how while it's typically clear when white supremacists are deliberately doing it for nefarious reasons, the fact that you'll never be able to be 100% sure and they can just hide behind innocent uses will be something itself that they revel in and is kind of part of their point.
So either you let them have the power to completely co-opt innocent stuff, or you don't let them have it, but instead because it continues to be seen as harmless and innocent normally be able to use the innocent meanings to gaslight people as to their real intentions. No matter what, whether they're able to change the meaning or not, they're able to score some form of "win" out of it, and they know it, and that's why I'm not sure how to handle this stuff exactly. Because no matter what you do, one way or the other it's playing into their hands and they can easily twist whatever response they get from it to suit their own ends.