the best answer is the story of the guys "down under" in OZ
some years ago..on a long treck in the outback they found the
only water hole had a dead and very rotten roo in it..the
horses would not even drink it..sooo..they strained the water
thru blankets..boiled it..put ashes from the fire in and boiled
it more..strained thru the blankets and let it cool and drank
..it still had a nasty taste but no harm came to them...