The worst experience I've had with a gritter involved popping my head up from a manhole just as one went past.
I had lovely bright red blotches across my face for a week!!!
In our 'home' town there used be a parfume and soap company. Whenever their bathsalt mix went wrong the 'end-product' was given to the council for gritting.
Some winters we had lovely smelling roads and cicle-paths (lavender, pine etc)