Do you have really stubborn scrubbing to do? Many commercial scouring cleaners have silica or chlorine bleach, both potentially dangerous substances. Silica can be harmful if inhaled, and bleach products mixed with other cleaners can create a poisonous gas. Bleach is also harmful to septic systems and releases unhealthy chemical byproducts into the environment. A safer method for scrubbing is a homemade paste of baking soda and a small amount of liquid soap. Try a test spot to make sure you don’t make scratches. Then scrub away. Commercial products, free of silica and bleach, are also available in local stores.