I don't believe that would work very well. There would be individuals that would abuse this for their own gain.
Big problem with that - I could trash anyone that I have a grudge with for no other reason than I have a grudge. You might not, but there are enough people out there who will do just that.
The best way is to know what your looking at, consider the coins are being counter fitted and even slabs are no guarantee. Buy the coin and not the plastic. If your not sure, ask and then pass if there is ANY question.