I use two old pickle jars. One for the Naphtha gas (Coleman stove fuel) to swish pellets around in and the other to pour the naphtha gas into after swishing. The gas will remove any wax, grease, etc. On the next round I switch jars to clean more. I pour the pellet on to a newspaper or an old t-shirt to evaporate, which is fairly quick. I lube them afterwards to prevent oxidation when stored, typically a thin layer of silicon oil. You would be surprised at how many lead flakes are removed on clean looking pellets. The wax removed is evident as well in the gas. All done safely outdoors or in a well ventilated area. It's much quicker and easier than soap and water, and more effective at cleaning, IMHO.