People change only when they are ready to, not before. It is an internal thing, there has to be a compelling reason.
Stop handing out free Narcan. The problem will self resolve.
Even people who shake off the habit are very prone to relapse!
By far, the best treatment is NOT to START At all.
But, if you listen to the modern woke gurus, experimenting is pretty much OK with precautions.
Kind of like you can have unrestrained sex, but do not forget condom!