I have some hunting land where I have an off grid cabin where I spend sometimes a month out at the cabin and I do have a generator to keep my cameras charged and a mini fridge going as well as my laptop and some lights.
But I have no washing machine out there or running water so I bought a mini hand crank washing machine to wash my laundry when I'm out at the off grid cabin.
The hand crank washing machine is easy to use and does a good job of cleaning the clothes and uses very little water to wash the clothes.
Then I just hang the clothes out on a clothes line at the off grid cabin to dry.
You can also use a bucket of water and soap and then use a scrub board to clean the clothes with like they did in the very old days when no washing machine was available.