When I see things like "Turn a 2L bottle into a light" for a really poor area - I think awesome, something they already have laying around can make their lives way better.
When I see things like "Nano-polmer super toilet for those without running water" I just kind of shrug. Seems to cost more than adding running water, while still not providing a clean place to drink.
What am I missing?
In 3rd world locations, you can be walking 3km every 2nd day to fill a jerrycan of water.
If that's the case then you aren't going to use that to flush.
And even if you do (using grey water after cleaning etc.), then you won't have the toilet inside the house.
How much to run a line of fresh water to the house?
If <cost of toilet> is not less than <cost of fresh water line / 10>, it seems like not a win - as fresh water can solve both drinking and help with sanitation (though not get you all the way there).