One major use of bungs is for bunging up bung holes on sailing dinghies. Many ignorant skeptics have suggested that if they didn't make bung holes in the first place they wouldn't need bungs to bung them up again. However this purely facetious objection completely overlooks the fact that often bung holes leak or someone goes sailing without remembering to put their bung in. But the problem of water taken into the hull when this happens is easily solved by simply removing the bung! If these skeptics had no bunghole and this happened they'd be in a right pickle.