Possible Clues:

• What the sly player uses when scoring a sneaky goal
• Halt set in furtive manner
• Hugger-muggery
• Supposedly invisible bomber, though the last crashed
• Furtiveness is the last resort
• Pinch most of the cautious approach
• The last appalling secret procedure
• Careful procedure the last resort?
• Secrecy over latest bomb perhaps
• Furtiveness with which one would doctor the salt