"A polished ball" is a vague, nebulous concept.
You can polish a ball that has a 500 grit base or one that has a 4000 grit base. You can polish with a lot of polish mixture, with a lot of pressure for a long time on the spinner or you can polish lightly with out a spinner. There is a HUGE range of potential finishes for a polished ball. It depends on what you want and/or what you need.
There is never one way to produce a "polished ball".
Just to note, The video which I believe is being referred to by JohnN is from a small 5 video series called Mo Know Sanding.
They can be found here:
https://www.facebook.com/pg/Wow-Thats-Radical-1127524493941579/videos/?ref=page_internalMo Knows Volume 1. Cleaning a Bowling Ball
Mo Knows Volume 2. How to duplicate a 500-1500 factory finish
Mo Knows Volume 3. How to duplicate a 500-2000 factory finish
Mo Knows Volume 4. How to duplicate a 500-2000 Compound factory finish
Mo Knows Volume 5. How to duplicate a 500-4000 factory finish
In the referenced video "Mo Knows Volume 4. How to duplicate a 500-2000 Compound factory finish"
He wasn't telling how to "bring a polished ball back to out of box".
He was showing how to reproduce the 500 Siaair / Crown Factory Compound factory finish done by Radical (Like on the Cyclops) on a spinner.
He said at the factory the high pressure machines go from 500 straight to compound.
But on a spinner you have to add in the 2000 step to get the same surface.
It wasn't really a general instruction on how to put a polished surface on any ball.