Empty an aluminum can of its contents and remove the label. Once empty, clean the can thoroughly, removing any particles or stains left from the contents. The size of the aluminum can will help determine the amount of water flowing from the shower during use. A smaller can will increase water pressure slightly while a larger one will spray a larger area with slightly reduced pressure.
Poke holes in the sealed bottom of the can using the nail and hammer. Like the size of the can, the size of the holes will help determine water pressure; the smaller the hole, the higher the pressure. The size and number of the holes will also determine how quickly the water flows out of the receptacle. For a longer shower, use smaller and fewer holes.
Seal the opened top of the can with a plastic bag and tape the edges down with strong tape such as packing or duct tape. This will prevent overflow and also provide a closed pressure system through which the water can flow from its source.
Make a small incision in the center of the plastic bag covering the open end of the can and insert the hose or tubing. Once inserted, close the insertion tightly using tape.
Connect the other end of the tube to the water source. If using a piping system, affix the tube to a connector that can screw into a water valve. If using a portable water bag or bucket, feed the tube through an opening in the membrane or casing and tape it securely.