Is there such a thing as a rust preventive for a chamber which
is NOT also a lubricant?

I am looking for something which can be used without the need
of cleaning oil from the chamber prior to shooting. Where I was
raised in western Nebraska with very low humidity, there was very
little worry about rust occurring with no rust preventive at all.
However, here in Iowa, humidity deterioration of steel is a far
different story. After 30 years of cleaning out the "lube" from
my chambers, I am sick and tired of it. There are times when it
cost me getting a predator because of the time involved.

What do you use?

Eezox, once it dries, it has no effect on the bore or chamber.

http://www.eezox.com/gun-care.html

http://www.thegunzone.com/rust.html

http://www.6mmbr.com/corrosiontest.html