Your white clothes come out of the washer with some small black or grayish stains? When was the last time you cleaned your machine?
It is sometimes neglected and yet, if there is a something in the house that is used regularly, it is indeed the washer.
No need to spend on cleaning products, ordinary vinegar does an excellent job, it is indeed an antibacterial, it kills germs and eliminates mold and soap residue.
Pour the vinegar into the drawer for the laundry, start a cycle with hot water and that's it! Repeat this once a week.
Small tip, I also add a cup of vinegar in the machine when I wash the towels, it naturally softens the fabrics.