Not at all Richard but I do want them to have their eyes wide open and be well aware of the problems of contamination. That is why I suggested they become totally familiar with the specifications and therefore what can and cannot be done. Then they will then be fully in charge of their own destiny so to speak.
I too have seen number one grade copper scrap remelted and cast into copper rod. Once, many years ago, I even saw a large nail embedded in the copper and jammed in a carbide die in a rod breakdown machine. The number one grade copper scrap was plastic strapped to light wooden pallets and dumped in the furnace.
We also had lots of rod shavings but I think the recast copper never went back to plants where it might be drawn to intermediate and fine wire.
Funny your comment about the plstic straps. I once had a General Cable metallurgist say that the plastic straps presented a bigger problem than the steel straps that they used before high strength plastic straps. I saw an "inclusion" that was about 2 feet long and looked about like a coat hanger wire.