"Foul water was backing up in the main drain due to debris. I introduced the drop scraper into the drain from the main inspection chamber and was easily able to drag the debris out. Job well done! Just beware that it has a non-locking attachment to the drain rods so could come unscrewed (it has a tendency to rotate in the drain). Wrap a piece of adhesive tape around the joint as a precaution against it becoming detached."