I have a black car and unless I keep a coat of wax on it it really shows paint swirls, I used tcut black polish last time and it looked excellent, is it safe to use such a product on a monthly basis?

The best way to remove paint swirls is to use an orbital polisher which if used correctly will eradicate them completely not just mask them (which waxing does). Its well worth getting this done professionally.
Is Collinite 476s no good then, Ive seen it mentioned on here a fair few times.

