Vinegar was originally used on cloth diapers way back when to “soften” them up and possibly as a disinfectant many years ago in the days of cotton and flannel flats and prefolds. However today’s modern cloth diapers do not need any further softening and with detergents that are effective and hot water settings, no additional disinfecting is needed either. Therefore, vinegar in the wash is not needed and could even cause odour problems if any vinegar is left on the diapers. Vinegar’s acidic nature can also weaken the elastic used in diapers or covers when repeatedly used or if diapers are soaked in a solution containing vinegar. It is not recommended by most cloth diaper manufacturers and may also void any warranties.
With a good wash routine, vinegar is not needed on cloth diapers.