Why use washable rags when you can use a diva cup?
I suspect the answer is the same in both cases: lack of clean water and effective sterilization methods. If you wash your rags in dirty water and do not expose them to the sterilizing UV rays of direct sunlight, you're giving yourself infections. The machine uses a UV light to sterlize, and does not require a reliable water supply.
When every village in India has access to ample amounts of clean-from-the-tap water, they may choose to revisit their current solution.
I suspect the answer is the same in both cases: lack of clean water and effective sterilization methods. If you wash your rags in dirty water and do not expose them to the sterilizing UV rays of direct sunlight, you're giving yourself infections. The machine uses a UV light to sterlize, and does not require a reliable water supply.
When every village in India has access to ample amounts of clean-from-the-tap water, they may choose to revisit their current solution.