3.5 hours tumbling today, I added soft scrub, home Depot media, aneal marks are gone, I think it works just as good as any other walnut shells if not better, I think I'll stick with the coarse, I had a bag sandwiched between the bowl and lid, no dust on the bag, it's basically a dollar a pound and works great, I definitely recommend.Thanks for the update.
Someone else talked about the dust so I will not use baking soda but will order the crushed walnut hulls from Home Depot.