Possible Clues:

• Employ one for good in ugliest reshuffle
• Find application or task for
• Exercise, in Exeter
• Put to good purpose, in Plymouth
• Put into employment, is seen in posh topper
• Unionist is wearing hat for exploit
• Would a lie suit one to employ it?
• Use (S, not Z)
• Exploit teachers' union broken up by new lies
• Employ uniform — form of cover is covert