Urinating in the sink.
Usually used by males, it is an act that is a lot more convenient, clean, and environmentally friendly than using the toilet.
Flushing a toilet uses about 1.5 gallons or almost 7 liters of water. Doing this 4 times a day uses 6 gallons, or about 28 liters of water a day.
Also, cleaning oneself can be done much easier by hittin a sinky.
Person A: Hey man I need to piss, where's your toilet?
Person B: Bathroom is down the hall but the toilet is broken so hit a sinky.
Person A: What's hittin a sinky?
Person B: Peeing in the sink.