Baking soda, also known as sodium bicarbonate, can be used in washing machines to help reduce odors, lessen the effects of hard water, and support the action of detergent. However, it should not be used as a complete replacement for traditional detergent. Using too much baking soda can leave white powder residue on fabrics. According to a report, a large tablespoon of baking soda — about 25 grams — is sufficient for a standard washing machine that handles around 5 kilograms of laundry. The best method is to pour the baking soda directly into the drum and then place the detergent in its designated compartment. Using more than this amount does not improve cleaning results but increases the risk of white powder appearing on clothes, especially if the rinse cycle is short or the drum is very full. It is also recommended to avoid the rinse cycle to prevent residues from staying on the fabric. Baking soda can also be helpful for washing machines that have a musty or moldy smell. Adding a few tablespoons of baking soda into an empty drum and running a hot wash cycle may help reduce these odors. However, this is not a guaranteed solution for removing bacteria or long-term limescale buildup. According to another report, white vinegar or a product specifically designed to remove limescale is more effective for dealing with hard water deposits. The ADEME, a French environmental agency, recommends descaling washing machines once to three times a year, depending on the hardness of the local water. It also advises leaving the washing machine door open after a cycle to allow the interior to dry, which helps prevent the buildup of odors. Baking soda is not particularly effective at removing most stubborn stains, especially those caused by grease. Its main role is to enhance the performance of detergent and help with odor removal. For worn or heavily stained laundry, traditional detergent is still essential. Laboratory tests have shown that baking soda is not very effective against most tough stains, especially those caused by oil or grease. Mixing baking soda with white vinegar can create a foam, but this does not necessarily mean the cleaning process is more effective. Vinegar is acidic, while baking soda is basic, so their effects can neutralize each other when combined. If both are used, it is better to apply them separately and follow the washing machine's instructions. Using too much vinegar can potentially damage certain seals or tubes in the machine over time. Delicate fabrics such as wool and silk are sensitive to changes in pH levels, so it is better to use a product specifically designed for them and follow the care label instructions. The same applies to technical clothing with special surface treatments. When choosing baking soda, it should be pure sodium bicarbonate, and it is not recommended to buy a version that is marketed specifically for laundry.