Thee were several threads on this topic last year. I've been experimenting with it for some time. Made my own jig so I could drill different size holes in different size shafts. Wrote an article about it which is in a past issue of Trad Archers World.
It works to a point. A good way to add a little weight if you're using a fairly light point, say 125-130 grains, and shoot a fairly light weight bow, 50# or less. However, there are a lot of newer heavier (175-200 grains and more) heads out now that obviate the need for an internal footing.
The problem with trying to achieve EFOC with wood is that wood usually isn't found in spines high enough to handle it. Loading up the front end with 250-300 grains of steel,lead or whatever, requires another 30-40# of spine or more. If one shoots a moderate or heavier weight bow, or has a long draw, it's just not possible to find wood shafts with sufficiently high spine. Fun to play around with though.