In my experience with coal and coal stokers, which goes back 25+ years, dry coal was thee best deal for the equipment. Vegetable oil on coal may be okay for a season, but it will continuously coat your coal bin and the build-up of old vegetable oil can cause issues ...as it does in the food industry where I worked for a number of years. But think what oil does to your kitchen walls and range hood.. Now imagine THAT inside your chimney. It's sticky and I cannot imagine how I'd get that out.
As for dust, yeah, it probably works great but at what expense???
If it works for you, terrific.
Vegetable oil? Industry standard? Not at all sure about that one. This I have discussed with people who should know, but I am open to being enlightened if all of my information is wrong. Let's get other coal people in on this discussion, I'd love to hear what they have to say.
My personal view on wet coal is one I will stand by. I firmly feel that adding water would destroy my Keystoker. As said, I spoke to the Keystoker, directly. The guys who build the furnaces are right there to talk to. At the time I talked to a lead engineer who, I beleive, is also an owner. Call for yourself and tell someone in-the-know that you actually add water to the coal. LOL. I'd love to hear the response.