Aus, you can remove the galvanize simply with vinegar. For your long lengths, just use a length of PVC pipe, say 1 1/2 or 2 inch, cap one end and fill with vinegar. In a few hours or overnight, your threaded rod will be nice and clean of galv. By using the PVC, you can select the length and size you need and save a lot on the cost of vinegar, which is pretty cheap anyway.