Related Clues:

• 16-Across residue
• Fireplace stuff
• Soap brand containing ground pumice
• Etna outflow
• Remains on the hearth
• Hearth refuse
• Barbecue leftovers
• Etna ejection
• Tray remnant
• Burning result?
• Campfire residue
• Straight-grained wood
• 56-Across's output
• Red river?
• Remains of a blaze