On the inside of the tubes just about anything will work great, up to and including waste oil from your last oil change. You know how you can still see that spot of oil in the pavement from that oil change last year? And that is oil that was exposed to the elements and traffic. Just oil on the inner tube will occupy all the nook, crannies, and pores in the metal. Being hydrophobic would stop humidity from getting in contact with the metal. Being protected inside of the tubes it will never degrade or move away.
Personally I use boiled linseed oil mostly because of old school snobbery.