Also, chewing on a whole clove kind of makes your mouth go a little numb. Hence Clove Oil being good for toothache, etc.
I'd definitely keep looking (or not looking, but with purpose. :p) for Ground Cloves. They're quite hard, and while I'm certain you could grind them in a mortar & pestle (and they'd probably taste & smell fabulous), I imagine it'd be a hell of a job!