This may be controversial, but I think the way to combat dog whistles like this is to overuse them and muddy the waters. Make it so the Nazi's aren sure whether the "pattern noticer" they are interacting with are antisemitic or not.
ISIS went from being an Egyptian goddess and a great band to a poorly translated acronym for a terrorist organization because everyone let the terrorists win on that one. The swastika has been a neat and simple symbol used by a variety of cultures with a variety of meanings ranging from positive to neutral until it was taken by the Nazi's. 88 is a really neat looking number that's done nothing wrong.
Society keeps on ceding cultural ground to assholes and the rest of us have to tiptoe through every piece of communication in fear of being associated with them.
What's next? How long until some fascists start to use the "cool s" that we all doodled in our notebooks in school? Are we going to have to stop using any numbers with less than 3 digits? Will Allah, Jupiter, and Thor join Isis as symbols of fear?