They're using it all over Cambodia apparently to remove pathogins in the water.
I found some info on the web about the process, or a similar one.
A handful of clay, yesterday’s coffee grounds and some cow manure are the simple ingredients that could bring clean drinking water to developing countries around the globe.Click here to read the DIY instructions.
An innovative new technology, developed by ANU materials scientist Mr Tony Flynn, allows water filters to be made from commonly available materials and fired on the ground using manure, without the need for a kiln. The filters have been shown to remove common pathogens including E-coli. Unlike other water filtering devices, they are simple and inexpensive to make.
“They are very simple to explain and demonstrate and can be made by anyone, anywhere. They don’t require any western technology. All you need is terracotta clay, a compliant cow and a match,” said Mr Flynn.
“Everyone has a right to clean water, these filters have the potential to enable anyone in the world to drink water safely.”
"Where you live should not determine whether you live or die."