It'll work. We just need a government that's serious about stopping it.
The vast majority of drugs (cocaine, meth, marijuana, heroine, etc) being used in this country come in from Mexico. Our government doesn't care about defending our borders and lets this flood continue unabated. We also have an entertainment industrial complex that promotes and glorifies drug use.
If we closed off the flow of people and drugs crossing our borders, treated drug smugglers and dealers like Al Qaeda, and shutdown "entertainment" companies that promote drug use, we could reduce the amount of drugs being used in this country by well over 75%.