Cow dung cakes are very useful for fire sacrifices (yajnas) and in various ceremonial activities. They create a pure and holy atmosphere when burnt. The smoke of gobar clears the air of germs. When we offer ghee in fire as part of ritualistic sacrifices, it strengthens the ozone layer and shields the earth from harmful radiations, it is used in Agnihotra puja as well.
Traditional wisdom says that in burning these cow dung cakes, the temperature never rises beyond a certain point, ensuring the nutrients in the food are not destroyed by overheating.