They actually cut tar with coffee grounds, at least the middle men did.
I used to get mine straight from the cartel back in the early 2000s, I lived an hour from the Mexican border.
But yeah the best stuff had such a potent smell it was almost revolting to the senses, like it made your eyes water. Drier and more solid in consistency.
How would you describe the smell? Like a burnt/BBQ/vinegar smell?
-GC