Read the following article and answer the question.

Uh ... head on upstream a ways to do your laundry . " Manji pointed with his chin . " You do n't need to hang out and watch . " " Why is that ? " Rin stopped some distance from the bodies when Manji set down the severed foot on the pile of discarded armor . He knelt by Ryonosuke 's headless body and rolled him on his side , exposing his left hand clamped on the hilt of Manji 's sword and the point still embedded in his belly . Manji turned his head halfway .

Why would you head upstream to do laundry ?
You can use the water from the stream to cleanse your clothes and it will be cleaner upstream .