With these types of vacancies to fill, firing them will achieve nothing (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
blanks
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for blanks that I've seen before include "Vacancies" , "Cartridges with explosive charge but no bullet" , "Explosive cartridges with no bullets" .)