I'm not sure specifically about Canada, but I did look into how needle swap programs and harm reduction were handled in some US cities: it was a train wreck. This approach does not work without adequate rehab therapists and resources to help people quit. If it's just decriminalization and needle swaps with no rehab, drug use goes up.
The fact that US citizens look at these programs failing due to insufficient resources on the things that matter and conclude the whole thing is bunk is a separate problem.