This is a great initiative. Interestingly, manual washing machines like this were briefly an incredibly hot commodity in even wealthy suburbs in my home city Cape Town, SA during the extreme drought and water shortages we had in 2017/2018 [1].
They used substantially less water than a traditional Samsung or LG washer and actually worked pretty well. Considering the draconian water rations that had to be put in place people were very keen to speed up washing while still very strictly controlling water use. The local brand that people used was called Sputnik [2]. Now that the drought has broken people often talk about how crazy in retrospect our water usage was before and I even know a few who actually still use these washers because of the efficiency. That said - most folks have gone back to machines now that the water situation is stabilised...