That is what has worked for me. I haven't had much luck tapping epoxy, but I was just using basic 5 min home depot stuff.
Like was mentiond earlier make sure the surface is cleaned and that you get the filler all the way to the bottom of the hole. Tooth pick works good.
Hope this helps.
My paint friend has some hi tech epoxy that is blue in color and dries pretty hard. That might be the ultimate fix for the plastic.
