Grey water is so underused it makes me wonder what we can be thinking.
In Japan you can buy bathroom sink/toilet set ups that use the sink water for the toilet flush, ready-made.
I set up a grey water education project in an area of Kenya when I was living with the Maasai there, as I noticed that
even in the midst of a years-long drought the wash water for clothes and dishes was just being thrown away.
We started small 'gardens' in heavy duty plastic bags for greens, tomatoes and onions, all of which are used a
lot in the Maasai diet, but the women had to travel an hour or more to the closest town to get veg that was days
old by then.
I got the backing of the local doctor and the community nurse, so that was good.
They have now started a larger garden in conjunction with the women's safe house,
which is an invaluable asset.