I use ground walnut shells, and add either nufinish, or any other polishing compound that I have. I use to build and repair guitars so I have some left over very fine polishing compounds. It is a very good thick compound, so I take a little out and let the moisture evaporate over a few days, crumble it up and add it to the media. They all seem to do a very good job.
The idea of adding dryer sheets or small pieces of cloth to cut down on dust is a great idea I am gonna try.
When the media gets dirty, I dump it all in a 5g plastic bucket, about a tblspoon of laundry detergent (low sudsing) and some HOT water, just to cover the media. stir it about and then rinse off the dirt and junk, slowly with cooler water. You will lose a very small amount of media, but the shells are soo dense they sink in the water.
Now, get an OLD sheet or pillow case to pour the cleaned media thru to get rid of the water, lay it out to dry and you can reuse your walnut over and over. Just re add new compound and there you go.