While not the best way, it is definitely one method of getting CO2 to dissolve into your water column.
As mentioned, the bubbles that come out of a regular airstone may be quite large, meaning that there is less surface area. This results in a slower dissolution process, wasting more CO2 (any CO2 that reaches the surface is wasted).
You can try having the airstone near a filter intake so that the bubbles become chopped up by the impeller or alternatively, have some kind of powerhead to push the bubbles downwards so that they have more time to dissolve (alternatively, you may want to angle your filter return to blow the bubbles downwards).