Propane and butane are inert...to most reactions but combustion.

Add fluorines instead of hydrogens, as in the case of difluoroethane in "Dust Off", and the gas remains unreactive and is less combustable. Add lots of fluorines and chlorines, and it becomes completely inert and damages the ozone layer.

There is a problem with using any of these gaseous products: once you've displaced the air in the headspace of your container and seal it, the new gas, because you have not bubbled it through the solution, will begin to dissolve into the liquid and create a negative pressure in the bottle, possibly inspiring air. Any gas will do this if it is added in the gaseous form. Gasses in the (temporary) liquid state will too, but when they evaporate they create enough of a positive pressure that when some gas dissolves there is still a positive pressure in the container to keep additional oxygen out.

But speaking kinetically, refridgeration is more effective for preserving oxygen-sensitive solutions than replacing air with inert gasses, at least over periods of a week or two. That is, if the solution's solubility isn't harmed by cooling.