New boat owner here.

I have a folding brass prop on my sailboat that aquired
a lot of barnicles. I have chipped off most of the barnicles but the
prop is far from smooth.

The boat sits in salt water near the mouth of a fresh water river.

My question is what should I use to clear the prop of the remnants of
the barnicles (sand paper? if so what grit) and should I treat the
prop with some kind of anti fouling paint?

Thanks
Steve