No! NEVER!!!!
We dont teach using a metal tool to scrape shellac off. If the shellac has been wrapped correctly for 10 mins, then massaged before removal an orangewood or Birchwood stick is sufficient enough to remove the softened product, if there are any stubborn bits of base coat or colour left I use a plastic backed pad and scrub the nail and it comes off easily.
No one should ever use a metal tool as you will more than likely damage the natural nail which undo's everyting that shellac is based on, Natural nail product.
HTH hunni
Jen xxx