your trying to create a yamadori style tree that is completly man made, i have about 25 of these in my garden bed all wired and bent and twisted to hell and back, a couple have died off.
what the technique you are describing does is the shari gives the tree a live vein where the nutrients and water are "pumped" up that section the rest is deadwood. you are supposed to start the shari quite small, bout 2-3mm (not sure of the imperial fraction, sorry) spiralling one spiral a year. the next year a little more is taken off the width of the shari and a bit more on the length and so on a so forth. what this does as the live vein swells it creates nice twisted trunk and more of a feature, as the deadwood keeps coming out it begins to flatten off instead of having a round trunk with a shari on it.
i am using that technique and i am also trying some others where i have wired pretty tightly as to let the wire scar the trunk, the wiring is sporadic not perfect as to look a little more natural, when the wire is biting in as far as i dare i take it off, then cut the shari in where the wire was if needed, this process will be repeated for the next 3-5 years or more, ground growing can speed the process up but the japanese have done it in pots the whole time
hope this helps some
jamie