Actually, if you were to pursue those lines of thinking, instead of using CO2, which contains oxygen and as I am sure most are aware Oxygen is a corrosive, use Nitrogen. N2 gas is pure, non-corrosive, and will actually absorb moisture. When in the Navy, we used it often to purge a system. We would evacuate the system to as low a vacuum as we could achieve, and then put a N2 charge of no more than 5 psi on the system and close it up. This process is known as "nitrogen blanketing" and is very effective.