It's most likely going to need a MOP (machine operated polish) and whether or not it's a rotary or dual action (DA) is entirely preference.
Unless you pay somebody else to do it. This could be worthwhile depending on cost. It won't be too cheap to set yourself up but when you do and have learnt your machine it's very rewarding.
DA's are 'safe' and rotary's have the potential to damage paint but you have to be a complete plum. Rotary's can eliminate heavier defects more quickly than DA's.
When corrected, explore using the 2 bucket wash method. If you already know about it I'll get my coat!
And I hope you know that sponges are the work of the devil!
If I've quoted the obvious forgive me!