I have had colleagues with (partially) similar behavior. The "help" they received from the rest of us was feedback. Sometimes it was public, as in:
Please stop moving so much, I cannot listen to you because I watch your movement.
(provided maybe with some smiling, so the colleague would understand it is not an attack)
Other times, it was as a 1-to-1 ...
Is there any really polite way to say such thing without being rude?
Not with words, but with a small gesture. It's my way to handle it when I'm in my office.
I usually pick a paper tissue1 and offer it to the person. They understand right away. I've never ever witnessed someone not picking up the clue. They say "thanks" and clean their nose.
FWIW: it also ...