I don't understand something ... if you only bead 1/3 of the 70" strand and then crochet it, what are you crocheting ? I mean what kind of stitch are you doing (chain stitch?) and are you using the unbeaded portion as well ? Am I making any sense ?

You string beads onto your wire, and then take your crochet hook and make a chain stitch. You basically take a few beads, make your stitch with those beads on the wire, and push the rest of the beads out of the way until your ready to make your next chain stitch. As you move the beads along, it uses up the rest of the unbeaded wire... You need more wire than beads to complete the chain stitches.