It is pretty much how China has handled it. It seems like it does actually work if your goal is to fully eliminate drug issues, but it's unacceptably harsh for most countries to palate.

Why is it expensive? Forced labor and for profit prisons exist.

And if there is a life sentence on hard drugs who would possibly have them on them?

You could also make it the 3rd offense or something, not that difficult.

Yeah, that is actually how a lot of countries in Asia have handled the problem