Stir it once a day until the golden hulls are hollowed out. They tend to swirl around more as the base metals are removed. Judging by the color of your solution and the amount of materials my guess is it still needs a few more days for the larger pieces to finish up. Cutting the parts in pieces can help speed things up, or just a deep scratch. The more the base metals are exposed the faster it works, to varying degrees.
Edit: cutting the materials at this stage isn’t recommended. Just let this batch run as is.
Edit: cutting the materials at this stage isn’t recommended. Just let this batch run as is.