Chris, I use the coal dregs from my coal bucket for my fireplace coal insert. I liked the effect also after noticing the sparkle when I went into the coal ' room '. Just that little bit of fine sparkly dust really works out well. All I did was apply some craft glue and sprinkled the fine coal overtop of the plastic coal load.
Right now I am able to run my modified Railking Triplex through about a dozen O31s in my over and under 16 × 5' double rail main layout with the caboose and 23 coal cars .
Have a ball Chris.
