Great camp gadget for scouts to wash there hands.
Empty washed out four litre milk carton with lid. Strong string or thin rope (5 mm paracord idea, but cheaper 2mm string will do the job). Eight wooden staves (approx 1.5m high, 15mm thick - see below), or branches you collect from campsite.
Select six wooden staves of approximately the same height. and use tripod lashings to make two sturdy tripods of about the same height. Make sure you tie the legs of the tripods so they don't slip apart and the tripods collapse (or drive the legs into the ground if it is soft enough).
Make two wholes in the lid of the milk carton, and thread a piece of string through one of the wholes. Secure with a stop knot on the side of the lid that will go inside the carton. Leave about 1.5m string to dangle from the outside of the carton. Fill carton with water and replace the lid.
Make a loop of string that goes through the milk carton handle (good time for a bowline if you can).
Thread one of the remaining staves though the loop and balance the whole assembly on the two tripods.
Make a hole in the top of the milk carton to let air in (water comes out through the whole in the lid).
Tie the remaining stave to the bottom of the dangling rope, and use as a footpedal.
Adjust the length of the dangling rope so you can put your foot on the pedal stave tip the milk carton till water comes out. Add soap on a rope for the scouts to use if you are on camp.