Rusty fuel tanks

["James " <dirmeyer@ix.netcom.com>]

When checking what I could of my fuel tank (of course it's off the car) I
spotted a few spots of rust on the top inside.  What concerned me even more
was a rather ominous patch of rust on the inside bottom by the fuel sender.
 The outside is in pretty good shape.  What's the best way of cleaning out
the inside.  Pep Boys suggested water.

I'm considering the cleaner, etcher, slush stuff from Moss.