There’s a better way. Simply execute the users.
But the drug lords won’t like seeing their customer base taken out by the government.
Let the drug users take themselves out..
The problem is the vast majority of users are here in the U.S.A., unless you meant American citizens vs. Mexican citizens? That’s basically how Mao got rid of opium use in China upon his takeover, they, and the drug peddlers, were all shot. End of story. I don’t know if there is much of a drug abuse problem in China anymore, however Mao killed tens of millions of other enemies of the state as well.