Aha you are re-amping, you want to use a pod pro, that has a switch on the front of it that allows it to accept line level (as opposed to HiZ) input.

You can go from the Korg Aux out to the Pod main input and back to the Korg as per usual, people do that all the time ! With a Pod pro you can even use the S/P DIFs to return the signal back to the Korg so you are only converting once.