You'll never stop it..Big cash see's to that.
If you take out the users instead the the producers - there's no big cash. It really is basic economics. Kill the market and producers go away.
Try and get a loan to start a buggy whip business. Can't - no market. Same principle.
No users = no cash which = no producers.
Spare the user to get to the dealer = still a demand with decreasing supply which = big money for a supplier. Guy comes in and sets up shop - the drug problem never goes away.