Hrm. Some people have said that an object could be broken down small enough to do no damage. This is difficult, but possible. The theory is that the pieces just need to be small enough to burn up in entry, rather than landing like bombs.

Your argument seems to imply that this would simply overheat the atmosphere into a firestorm. If so, that renders one option completely nonviable -- and there are plenty of people who think that "bomb it to gravel" is viable.