Lapping compound - non-embedding

Hello Jewelry peeps, does Jewelry have any non-embedding lapping compound? Garnet or silica based - coarse is what i’m in need of. Specifically not diamond based.

I’m in the process of making a set of 3 round lapping plates inspired from Oxtools YT series here. It involves the Whitworth Three Plate Method of rubbing 3 surfaces together in a prescribed order and pattern etc. My plates are 7 inches in diameter with pre-1982 copper pennies glued to the surface and then ‘faced’ with my lathe. I purchased 2 cans of Time Saver lapping compound from McMaster-Carr per Oxtools suggestion. The Fine and Superfine… It’s working but quite slow as it breaks down fairly quickly.

So I thought I would inquire to see if Jewelry has some course grit compound I might be able to try. I’d be glad to donate some of my compound as well.

PS - Once I get them flat, I will be switching to diamond paste as the copper can be charged with diamond grit at that point. I’ll most likely dedicate each plate to a specific diamond grit at that point

The cutting compounds we use typically use contain aluminum oxide. I’m not sure if this is considered non-embedding.