The answer to tough stains on dryer vent is that they are often caused by lint buildup, debris, or grease. Symptoms include reduced airflow, longer drying times, and visible stains or discoloration on the vent. Solutions include cleaning the vent regularly, using a dryer vent cleaning kit, or calling a professional vent cleaning service.
Homeowners can try DIY cleaning methods like using a dryer vent brush or compressed air to remove lint and debris. However, if the vent is severely clogged or difficult to access, it's best to call a professional cleaning service to ensure the vent is thoroughly cleaned and any blockages are removed.