It is easy and cheap to polish your porcelain sinks and bathtubs with just baking soda and dish soap or liquid soap.
1. Mix the soap with the baking soda to form a thick paste;
2. Add a bit of water;
3. Rub the paste into the porcelain to remove scratches;
4. Rinse the area with clean water;
5. And fill the tub with warm water and some bathing salt;
6. Enjoy a relaxing bath without worrying there is any harmful chemical left behind.