Without soap: Mix clean riverbed sand or light gravel with a bit of grease or oil and some wood ash from a fire. Add a teaspoon or two of hot water to make an abrasive paste. Some people use warm coals from the fire instead, but either way, be careful as the cleaning paste can be harsh on the hands. The combination of these products causes an acidic reaction. Rub it over all your soiled cooking and eating equipment – it looks like you’ve made even more of a mess – but it does work. Rinse clean, well away from a water source, not forgetting to clean your hands afterwards either.