balsa lures

I saw an article where a lad doctors his balsa lures. He drills and puts split
shot in them to make them neutrally bouyant. The effect is they are more easily
worked and effective. Particularly if you are fishing from shore and can't
drive the lure down by rod positioning. I have tons of balsa lures but i don't
feel i'm getting maximal advantage out of them. They also seem to be for sale
at flea markets etc. I think it would be a real blast to change a dog of a lure
into a top producer.