The washing machine rinse cycle (including a second rinse), generally fails to rinse detergent residue out.
Plus, laundry detergent residue, from clothing, may harm your skin. What’s in your detergent?
Whether powder or liquid, most detergents contain thickener. Thickener may even retain dirt after a rinse cycle.
For a thickener free, non-detergent fabric cleaner, here is a good place to start. These will not only dispense swiftly in the wash mode, they are extremely quick to rinse 100% out.
Under normal conditions, there should be no reason to do a second rinse. Because stain removers and concentrates may further hinder the rinse, for us it is better to avoid them. Also, thickeners may contain odor retardants and fragrance to mask chemical odor.
A good first step in clothing care is to clean your washer.