I use the baking soda with a dash of dish detergent and simmer then let cool down. Go at what is left in the pan and repeat as needed. Sometimes it takes multiple days of soaking and scraping the top off. Sometimes I use the edge of an old teaspoon or soup spoon to get under a particularly crusty spot and pry/pop it off. This is particularly useful, when the steel wool pad only seems to be making the top of the burn shiny.
Diana