The Marines coming back onto the ship from the field had some funky laundry. You do it however you have too. A lot of times over seas I had a local person do it. I buck or two to wash a bag a laundry is a good deal. I didn't have to do it, and the local economy got a buck or two.
Usually in the field we just stunk real bad. Baby wipes are a soldiers best friend in the field.
In Iraq KBR did it.