Maybe you can have advance air support. A drone with an IR laser targeted by a lens detector. But you'd need to avoid targeting people wearing glasses.
But no, that's silly. Really, you just need to give up on the idea of being anonymous in public. Because that was never something that you could count on.
That would likely just flag you as someone trying to obfuscate facial recognition. Making you quite unique, no?
I have noticed that it's very hard to recognize faces of people with very black skin, under low-light conditions. So I can imagine black makeup that's 100% non-reflective across a wide range of wavelengths. But then there's millimeter-wave radar. How would one block reflection of mmW radar?
But no, that's silly. Really, you just need to give up on the idea of being anonymous in public. Because that was never something that you could count on.