There has to be some hole going through it somewhere. It may even be a small hole (1/4" maybe) to put the core through and plait on top of it. Otherwise there is nothing to hold the plaiting onto the handle. I do something similar with my whips, but I usually cover the handle. I start with a 6" stainless nipple. I use an 1/8 piece of round nylon rope and start plaiting my core about 6" from the end of the rope. I'll plait 4 layers at varying lengths to start my taper. then once I am about the diameter of the inside diameter of the nipple, I will insert the core. I will tie some small washers along that rope end that I left un-plaited. Now I cap off the end of the nipple, fill it with epoxy, and insert the core. wipe off the ooze, let it cure, and now I have a nicely weighted solid handle with a rock solid core. I should mention the cap I use is a perfect foundation for the butt knot.