Hi, I need some help with polishing options please!

I have made a river resin table using glasscast 50. I used a metallic tinting pigment, it looked a lot more opaque in the bucket than in the final outcome which is mostly transulscent.

Having sanded (currently at 120 grit) I prefer the matte and opaque finish - partly because its truer to the colour I was after originally, but also because I made a few mistakes in the resin which thankfully disappeared under the cloudy effect after sanding.

What polishing options exist which will get a transulscent glasscast 50 to polish up to a cloudy sort of matte finish that will mask any minor problems in the resin eg I tried to drill out a dust spec and fill with an attempted colour match which didnt work at all

N.B I’m planning on using a clear osmo topoil on the wood.

Any help much appreciated

Thanks

Chris