Did you try angling the head so it is not perpendicular to the bars? It looks like the "teeth" spacing is oversized and the intent is you angle the head until the teeth fit on the bars of your particular grill. Doing it that way it looks like it should fit most any grill. That said I don't know how convenient the scraping action is when you are holding the tool at an angle to the direction you are pushing.
I've had one of these for a few years, and Jim's description is right on. Mine works just fine, except for the screeching noise I get from it sometimes when I'm using it in a hurry or at the wrong angle. Sort of like fingernails on a blackboard but not as bad.