Clean water and sanitation access in Burundi is rapidly improving thanks to many international aid programmes, so perhaps this invention is not needed there—the country is bordered by freshwater lakes, after all.
Your point still stands, but the $4 wouldn’t be paid by end users: it would likely be covered by these organisations, which would then be able to provide aid for a much larger population.
Your point still stands, but the $4 wouldn’t be paid by end users: it would likely be covered by these organisations, which would then be able to provide aid for a much larger population.