They do make very small "portable" wash machines they work off of sink or tub hook ups mostly.
If going off grid, go for the old fashioned wash board and a mild soap in the tub.
Not that I recommend shopping there, but here is an example for sub 250$ and under 50#. https://pic8.co/sh/bzjrBr.png
Like what? Dr Bonners?
I misunderstood your Q.
Try here. https://www.cappersfarmer.com/farm-and-home/laundry-soap-the-old-fashioned-way-zb0z1810/
If really concerned what goes in. you can skip the oxyclean. You can even go as far as the old bar laundry soap alone or the arm & hammer alone. They tend to work a bit better mixed though.
See my edit. I was in the process of grabbing pic for pic8 instead of linking to that shit place.
(post is archived)