An old guy like you should know.
It was very popular years ago, but it is still available. It is a "pummus stone" looking thing, black, about six inches, by two feet by 18 inches. You cut off with a saw what you need and then you just start rubbing on the plastic filler on the car. It shapes it's self to the shape of the car. So, after some sanding it starts taking on the shape of the bodyline or what ever you are sanding on.
The "stink" comes from it smell, the stuff stinks.