Pathing tool

[Ofnuts]

Several ways with https://www.gimp-forum.net/Thread-ofn-path-edits

• Make a selection (lasso, rectangle) around the strokes and call the "delete strokes" function
  
• Use the "Break path apart" to make one path per shape/stroke and delete those you don't want
  

There is a HTML in the zip with explanations/examples.