re: other fluids
Dang if I know.
CO2 is good at dissolving covalant compounds, less good at ionic. (less than water, anyway, which is real good at ionic compounds due to the polarised H2O molecule).
CO2 is good at light organic molecules, some sulphur compounds (but I don't know what), also Halogens.
Remember this would need to be liquid or supercritical CO2 - vapour doesn't work the same way.