When I served in Vietnam, our latrine (privy) was a 3-holer, with standard seats attached. Underneath were 55gal metal drums, cut in half, and every few days a local gentleman would come by, pull them out, pour in diesel fuel, and stand there stirring until the contents were semi-burned. One of my better memories of the period was, when our compound was hit by a typhoon, watching the latrine blow away and those drums roll off downwind.