The inflow/manufacture of narcotics won't be affected at all. You'll still have a constant new influx of junkies, and it you'll essentially by funding this widescale and expensive solution forever.
Much better to simple make drug trafficing and manufacture a capital offense. It's been extremely effective in a lot of jurisdictions. Even if you're squeamish about the death penalty, a back of the envelope calculations will tell you you're saving a lot more lives than you spend due to decreased overdoses, drug wars etc,