So, almost a year later. I never tried the apple juice starter. I figured that if the goal is to grow more yeast cells, rather than just to let them turn sugars into alcohol, that a balanced culture media makes more sense, i.e. a barley wort based starter. To be honest, I haven't done this yet, either. I have about a dozen half finished projects laying around. But, the way I see it, if you make a regular starter with DME, let the yeast settle, decant off all the extra fluid, and just use the leftover slurry, the little bit of remaining wort is not going to affect the taste/character of the final cider. I hope.