Ohhh ok. You probably want to check out the Nylon sleeving like I was talking about, it feels more like a fabric, rather than a plastic, which I am assuming Techflex feels like. It appears that he just used the nylon sleeving and heatshrinked, or something similar to it, the wires at the Y after stripping off their outer casing of course.
I heard something about shrink tape, simply applying it and it shrinks without the need to heat up which I might look into it. The Y section still might need one of the ones I linked too, I might even add an extra bit of tubing.
Sleeving after the Y does look stunning but I don't think it would work in this instance, I'm planning to recable a Sony XB500 and I'd like to re-use there sleeving.. as seen here (the bit the wire goes into before the headphone):