It has been tried before Halzey, it was found that with normal hempy's it didn't really have any real benefit from adding an air stone. The rez gets used up very quickly, and because you are always watering and the water has to trickle down through the medium, it actually aerates the water as it flows down into the rez, IMO a better thing would be to aerate the nute solution before you feed your plants. I like to bubble my nutes or water for 24 hours before I feed my plants and it provides plenty of D.O, but you could always try it out and report back to use, because I am always open to ways we can improve everything, but I myself don't think it will really help much at all.
Also as Toke said, the greatest thing about this method or hempy's method, is that there is no moving parts, nothing to break or malfunction, no worries of dissolved Oxygen or root rot, but you can still achieve a phenomenal growth rate that will rival other active mthods such as DWC, that totally rely on moving parts.
I am known to overcomplicate things for myself at times but with complication comes problems, so the point of this method was to avoid the complications while still keeping a very nice growth rate.
Great question Halzey