Most scent molecules are high or low pH, or very easily oxidized. That is why this recipe works well. Baking Soda has a very strong neutral pH so it will neutralize the high or low pH molecules and Hydrogen Peroxide will oxidize the kind of scent molecules that are easily oxidized.
2 quarts Distilled Water
1.5 quarts Hydrogen Peroxide
.5 cups Baking Soda
1 oz. unscented laundry detergent
After thorough mixing store in bottles that won't let light through. Light will reduce the shelf life of this product. Also keep caps loose for a week because this concoctioin will generate some gas and the bottles may come apart violently. Or the way I like to say it, "Rapid, Random, Disassembly".