Not much can beat a sky burial. Tibetians sometimes still do it. If you search around, you can find a photo sequence documenting it. The only notable modernization is plastic aprons for the workers. They strip and slash the body, then step back and let vultures eat. After the vultures have left only large bones, the workers smash up the bones with a bit of oatmeal in a bowl. The vultures like that too, ultimately leaving nothing uneaten.