Break-Free CLP won the test on www.thegunzone.com
for rust resistance . Ezox came close .
They say you should clean and wipe down an unused gun every 3 months but I never do .
One guy kept his guns in a dehumidified safe for years ( 10 or so ) without touching them . The Birchwood Casey Sheath oil he used eventually gummed up but no significant rust occurred .
The important thing is to try to coat all metal surfaces with a light coating of oil such as BreakFree . Gun grease may be better but is a mess to remove .