I think the halo-problem can't be solved through chroma-shifting, since it's a BRIGHTNESS-problem... I guess the exorcist-filter works by multiplying an inverted version of the image on top of the original (but only in the overlapping parts, caused by the given offset). This results in bright areas getting darker, and dark areas getting brighter, which in most cases is fine. Unfortunately, some dark areas (like those which were black before) don't need to get brighten up, and so this causes some errors.

I have found a little workaround for this through AviSynth, although by this workaround only the bright-halos get removed. But since these are the most visible ones, I think it might be an option. I'll post the script and some screenshots later.