To use a drill bit in this fashion, you must choose the correct bit. A bit that perfectly matches the thickness of the stock. Once we have the best match for a bit, we can scratch a line along the cutting edge. Use a very hard, flat surface and keep the drill bit and knife perfectly flat as you scratch the line. Then flip the blade over and scratch another line. If everything is perfect, you get a single line. That's rarely the case. I usually get two lines, extremely close together.
Here I am checking the lanyard tubing to see it fits into the F bit sized hole.
As a wee bonus, I did some filework on the spine.