It's impossible to end any trade for which there is a market. Drugs, sex, nuclear weapons, state secrets, etc. all seem to create markets to satisfy demand. It might be that the best way to protect innocent lives is to actually encourage the development of the markets to keep them above board and in the public eye.
I would guess that one would only want to create a legal market for an illicit good when the illegality of the market is causing more harm than the market transaction itself. I think that many countries, for example, have tried legalizing prostitution as a way of tackling forcible sex trafficking, unfortunately as far as I've read these efforts have failed to thwart sex trafficking.
