The answer to 'tough stains on dryer vent cleaning' is that tough stains in the dryer vent are usually caused by a buildup of lint, debris, or even mold and mildew. These stains can be difficult to remove and may require more than just a basic cleaning. Symptoms of tough stains include reduced airflow, longer drying times, and potential fire hazards.
To address tough stains, you can try DIY methods like using a dryer vent brush or compressed air to loosen and remove the buildup. However, if the stains are severe or you're unable to fully clean the vent, it's best to call a professional dryer vent cleaning service. They have the right tools and expertise to thoroughly clean the vent and ensure it's operating safely.