Abrasive to polish plastic

Apologies this is slightly off topic but I figure those who frequent this particular forum will be experts on this matter.

I need to polish some plastics to a HIGH shine (plastic equivalent to mirror finish in metal) using a bench grinder and cotton wheel. I have tried the blue josco wax bar JOSCO Polishing Compound Light Blue MULTISHINECARD | Total Tools

It comes up pretty smooth but it isnt a high shine. Plus the things I will be polishing has a someone irregular surface so the wax builds up in the valleys and is a pain to clean off.

I am thinking it would be better to buy some abrasive powder, then mix it into some glycerin so it is a water based (easy to clean) polishing paste that I can charge the wheel with. The question is, what abrasive powder should I get and what micron? I will need quite a lot of it too.

When I use CA on my pens I use Brasso after fine sanding and then use Meguiars PlastX polish which is designed for plastic

I've recently come across Kustom Creations Kustom Grit which is made in Brisbane.

Lots of makers on Instagram rav about it!

Kustom Grit Set | Kustom Creations