I just found the green .5 micron sticks of Chromium Oxide at my local WoodCraft store in the aisle with the hones. They sell it as micro fine honing compound. In the store the packaging does not have the grit size but their website Buy Green Chrome Oxide Compound, 6 oz., Green Chrome Oxide Compound, Buffing lists it at .5 micron. I used a cheese grater and some neatsfoot oil to make a paste for my paddle strop. But the item is intended to be used on a slow buffer.
Sean