For the record, I don't to anything to my coal. Just open the bag, and shovel it in. If I had bulk, I still wouldn't. The flyash makes more of a mess than coal dust ever could, IMO. I don't even notice that until visitors point that out. I tell them - you don't like, don't visit. Works for me.
BTW, tranny fluid is THE BEST used oil to burn. It's clean & burns really easy.
I've got probably 60 gallons of used oil out in the barn. Once I get a stoker furnace I have hooked up out there, I might install a drip system onto the burn plate. Might make a mess, but at least the barn will be warm when I need it to be.