Do you really understand how beating the daylights out of something can actually get it clean? I’ve read about some road warriors’ makeshift washers (a new plunger stuck through a hole in the top of a bucket of water w/detergent in it), but just physical force? What happens to one’s delicates? I’ll think about that tomorrow.
I used the plunger and bucket method of washing clothes for three years while the late Igor and I were Camphosts for the USFS. It was a fun gig, and I didn’t mind washing a few things at a time. I could hang them up and let the mountain/desert air dry them.
The delicates survive, since they don’t need the badgering that Levis need.
If vehicles are involved in your lifestyle, placing the clothes in a tub or two with water and detergent, and taking them for a ride on a bumpy road will provide all the agitation you'll need. Then it's a rinse or two and hanging them out for the fusion-powered clothes drier.
Wringer washers may or may not be available, but the same type of wringer is used for mop buckets.
Come the (rest of the) apocalypse, I expect all of you to have your appropriate Plans B and C in place, and your vestments looking spiffy.