here is the procedure i sometimes use to clean film scratches in flame:
assuming combustion has a “median” filter/operator, create a layer which has a median filter applied to it, preferably only in the horizontal directon. median filter keeps the overall color info but destroys the details, hence the smooth look.
create a mask either with gmask (which you can track or at least animate) or with paint over the face of the talent and reveal the “smoothed-out version” you created with median
i hope this helps…
sinan vural