how about mixing a little epoxy with talcum powder until it still flows under gravity and by dribbling apply just enough over 4 or 5 hard setting applications until the holes are filled or small enough to re-tap with the screws.
Only epoxy though, it's a true adhesive and could quite possibly make the thread stronger than original.
Another way is to drill each stripped hole out to a tight fit for some sort of solid plug. Coat the solid plug with epoxy as well as line the hole with it then tap the plug home, you can even use a hardwood dowl for this because once the dowl is coated in epoxy it wards of rot fairly well.