Once the soap has melted entirely, remove the pan from the heat. Immediately pour in the baking soda and salt mixture and stir energetically. The ingredients will begin to combine into a uniform, creamy paste. Make sure the texture becomes smooth, without lumps or visible separation.
Next, while the mixture is still warm and pourable, transfer it into a clean glass or plastic container. Leave it uncovered at room temperature for a while. As the mixture cools naturally, it will gradually thicken, ultimately transforming into a dense paste with a consistency ideal for cleaning.