The white distilled vinegar should be placed in the fabric softener dispenser so it will be added during the rinse cycle. Fill the fabric softener cup to the top level with the white vinegar. If your washing machine does not have a fabric softener dispenser you can pour it into a Downy ball, toss it in at the beginning of the cycle and it will be released during the rinse cycle. If your washing machine does not have a fabric softener dispenser you can pour it into a Downy ball, toss it in at the beginning of the cycle and it will be released during the rinse cycle.