Related Clues:

• Dutch shoe
• Footwear that's hard to run in
• Clone, for instance
• Massive impasse
• "If at first you don't succeed" course of action
• Block the pipes
• Become blocked
• Cousin of a 55-Down
• Reason to call Roto-Rooter
• Alternative strategy if things don't work out
• Facsimile
• 'Roger that'
• Drain blockage
• Make a backup of
• Emergency strategy