Possible Clues:

• Harsh or corrosive
• 'Sounds like a biting stick for a crow, by the sound of it (7)'
• 'Does the end of 13 across stick to the end of this, by the sound of it? (7)'
• Scathing about magistrate not taking sides
• C.A? Oh, that's so, Da
• Stinging bill rises and is cut, perhaps
• Acid
• Burning — cutting
• Sound of the crows might make sound of the clock sound biting
• Might so Da follow this to make the sound of the crow stick?