I have never seen or smelled either. What I do know is:
Meth is made using some of the nastiest, most volatile chemicals you can imagine. When a meth lab is discovered in my rural northwest area, it costs at least $50-$100,000 to bring in a hazmat team to clean it up. That cost is borne by the local taxpayers.
As a school principal, I would sometimes smell chemicals on some young students. It raised suspicions and concern for their safety. I would relay that to our liason officer. Exploding trailers are not uncommon in this area.
I would consider it an extreme concern if I lived near makers or users. It is a culture of danger in many ways.
Peace
warren