It probably wasn't even drug related. Sounds more like they were roasting green chiles, and of course they all left when the roasting was done. They had to hurry home and peel those babies.
Sometimes Anglos don't understand the cooking smells of other people. Green chiles emit just the odor described when roasting.
That said, I have seen marifoofa grown in chicken yards in Mexico. The have to put chicken wire around the plants to keep the birds from eating them down to a nub. They know a good thing.
Reminds me of these two old Mexican ladies I used to know. They raised it to sell, but when they got busted, they told the Judicial that they used it to make a linament for arthritus. They whipped it up in a blender with olive oil, some sort of little chiles and some other herbs.
Not only did they get off on the marijuana charge, they sold the judge two bottles of the stuff.
Rufus