Hi,

Have you ever tried the method of distilling salty water or other impure water by collecting the steam on a cloth placed over the top of the container while it's boiling? You would have to use several cloths if possible, one after the other and lift them off the pot with a stick to avoid being scalded and when they have cooled you wring out the pure water in them. I guess the problem is it would take a lot of fuel.

Frankie