Possible Clues:

• One may appear heated, but that's just nonsense
• Bombast makes tax officer retire in shock
• Bloviator's excess
• Bombastic talk or balloon elevator
• Empty talk? It helped the Montgolfiers
• Empty talk over the Sahara?
• Just talk, nothing more
• Locks securing books, nothing worth listening to
• A lot of campaign rhetoric
• What a balloon or showoff is full of