(You will need two buckets that are the same size to make this effective.)
Two buckets equal in size when filled to the rim will hold about the same amount of water. Neither bucket has a hole so, as long as they are not moved, they are equally effective holding water. However, one bucket has a bail, or a handle to carry it by, and the other does not. Have you ever tried to carry a bucket without a handle? The water will slosh out and you usually spill most of the contents. The bucket with a handle is easily movable, and the contents can be carried with little or no spillage. (You might have two Scouts demonstrate moving the two buckets.) People are sometimes a lot like the buckets. Some are out of control; leaving splashes everywhere, they go for someone to clean up after. Others are like the bucket with a handle, leaving no mess or bother. Which kind of bucket are you?
