Possible Clues:

• Ineffective
• Ineffective without a canine?
• Sloth is so ineffective
• Lacking power, be more patient when driving round horse
• Unable to chew; ineffective (sanction)
• A quick trip round harbour, at first, on sailing vessel that's lacking power
• Deprived of power, and adjusted to the loss
• Ineffective as gum without attachments
• Descriptive of Nobby Stiles when he was unleashing biting tackles
• Lacking in force