Definitely feasible, this shot was done with a 60Da and a 12nm Ha and OIII filter.
http://www.astrobin.com/full/98888/0/
The Ha was shot near new moon and the OIII was shot near full moon, Astrobin has averaged these and therefore reports almost 50% moon phase.
The 12nm OIII was definitely affected by the moon, not ideal but still way better than unfiltered.
The noise in the green channel OIII was definitely lower than the red and blue channels for the same ISO and exposure, benefit of the two greens in the bayer being combined. Half the noise? maybe.
I then combined the green and blue channels for further noise reduction, then mapped them back to green and blue.
Whether this makes, say, 9 of OSC OIII subs equivalent to 27 of the Ha with regard to noise, I don't know(I might try measuring one day) but it seems to work well enough
