Distress Selection

[Ofnuts]

As far as I can tell:

• Add new transparent layer
  
• Bucket-fill selection
  
• Filters>Noise>Spread (give a width)
  
• Blur (with radius somewhat smaller than width above, depending on smoothness)
  
• Add layer mask, transfer alpha channel
  
• Apply threshold on mask
  
• Blur result for something a bit smoother
  
• Apply mask
  
• Alpha to selection