Well, curiosity got the best of me, and I decided to try the soot from a candle to help prevent the solder from sticking, and to try dumping the molten solder into the mold instead of using the mold to melt the solder.
I used the candle to blacken the mold, you have to stick the mold into the candle flame to get the soot on it. I then made a hole in a small piece of aluminum and threaded in a long screw as a handle to melt the solder in. I also tinned the end of the cable before placing it in the mold.
I then heated up the mold, and then switched the torch to the aluminum cup and melted the solder. You evidently can't pour molten solder slowly, and when I tipped the cup the solder just flew out in a molten lump. I scraped the excess off quickly with a piece of wood. I let it cool a few minutes until the shine was gone from the surface of the solder and it didn't move when I poked it.
I then took the mod apart, and the first half came right off!
With a little filing to get rid of the cone at the bottom.....it looks great!
If you are only making 1 or 2 cables and you have a lathe, it is faster to just make a brass fitting and solder it on. If you were making a bunch of cables, have a drill press and a hacksaw - it is probably worth making a mold.