This isn't fully evaluated, since I don't generally do cosmetic repairs. I feel that holes are natures way of improving ventilation and drainage, but I had some aluminium foil and sunflower oil left over so I crumpled it into a hole in my sill and burnished it down by rubbing with the rounded end of my T-bar. Took about 3 minutes.
Been in situ for maybe 3 years now. Not much use to me but I think it'd work well for filling holes in door skins, if you like that sort of thing.
PRO's : No shelf life, won't attract moisture or promote corrosion (at least not as much as polyester filler ), can be obtained in Taiwan (unlike filler) , could probably be sanded (untested)
CONS : Won't do shallow scratches (at least unmodified), fairly pointless (like polyester filler).[You must be registered and logged in to see this image.]