When adding a new bathroom to our old farmhouse, we discovered the septic vent stack to be chock full of bird nesting materials. We were adding a 2nd floor toilet, and when the stack was opened up, there was straw and the like packed in as far up as we could reach. How would you recommend cleaning this stack? I can access it from top fairly comfortably. I plan on getting the top screen/wire covered when we're done?