First saw this idea shown on the Leyland Brothers way back when. They used a 20 Litre bucket with clip on lid ( I think it was a chicken feed additive bucket) and have copied it on a trip to norwest NSW and it work a treat.
I found I needed to use half the recommended detergent (probably front load washer stuff would be better) for one day, and then the clothes spent the next day in a bucket of clean water and rinse aid (again, half strength) for a 2nd day. Hung out over night and the clothes were dry . Four days of clothes for two people were a load.
Girlfreind at the time said the clothes were cleaner than if they came out of a washing machine. I wouldnt know, it was her job to wash the clothes!