Preheat oven to 350 degrees Fahrenheit.
Grease a baking sheet with nonstick cooking spray.
In a small bowl, mix together the salt, olive oil, white vinegar and water until combined.
Spread the baking soda onto the prepared baking sheet in an even layer.
Pour the liquid mixture over the baking soda and spread it evenly with a spatula or spoon.
Bake for 15 minutes, stirring every 5 minutes to ensure even baking and prevent burning.
Remove from oven and allow to cool completely before storing in an airtight container for future use.
