The answer to 'tough stains on dryer vent' is that common causes include lint buildup, dust, and grease accumulation. Symptoms may include reduced airflow, longer drying times, and potential fire hazards. Solutions can include DIY cleaning with a dryer vent brush or calling a professional vent cleaning service.
Homeowners should inspect their dryer vent regularly and clean it when they notice reduced airflow or longer drying times. While basic cleaning can often be done DIY, it's best to call a professional if the vent is difficult to access, has significant buildup, or shows signs of damage.