Yep, mainly you'd use this if you where escaping to higher ground by, as you said, running up the cliff face and knocking down rocks to put an obstacle between you and the opponent. Aiming for the higher ground is always a preferable option in battle as it gives you a better view of the battlefield and allows you to see attacks coming from your opponent better.
Hold out your dominant arm like you would be holding a sword and point it forward, then gather your lighting chakra into you extended hand and release the chakra as a pale yellowish glow. Then, shoot the lightning so that it is shaped like a horn, with the bolts of lightning spreading out to hit my clone, tell me where the bolts hit him of course.
Since it can be used against multiple targets I think you can see the value in this jutsu?