I have also looked at "Natural" filters, combo of grass/dirt/sand and cloth.
Read that SERE manual I posted. It has a "how to" for a makeshift filter. Just about everything you can find in nature except the can. I bet if you had to, you could figure a way to make it with out a can. Hollow log maybe.
Hey J.J. that is a great reference material. thanks for posting it.
Tue May 03 2011 0457 am
Posts 493153 & 493154
Doc and I became....
JYD Brothers of the Clock!