Topping and airlock maintenance are cheaper and very effective. Just
top your wine to withing 1/2" of the neck and cover it up weith an
airlock or stopper if it's still and the temperature will remain the
same.

You can do the CO2 thing, but normally you bubble gas through a
dispersion tube into the wine. The inert gases make much more sense
than CO2 as Rob stated. Just a heads up, there are different levels of
quality (grades) for gases, I'm not sure I would use just any source.
It may be worthwile to contact the manufacturer to be on the safe side
when using it for food.

Joe