I remember hearing an interview with some health-safety expert;
he was commenting on the lack of drinkable water in some of the areas hit
by that monster tsunami.
Apparently, some study showed that if you’ve only got ghastly water
to work with, filtering it through about four or five layers of
cotton material (like a T-shirt) will strain out a lot of objectionable
bugs.
I’d never try that unless TOTALLY in a life-or-death situation!!!
Guy is an idiot.
I would build a fire and using the black coals, sand and dirt, in a tube or bottle might do it.
I would use the cotton to filter what I could first but not in the method you described.
I have 8,000 coffee filters in storage for that purpose. Then after filtering, of course, I will boil it.