If you really want to get something very clean then add 1/4 cup of Borax and use Extra Hot if your washer supports it. Source - me - I wash household blankets the kids make super dirty sometimes. If the material can handle the heat (no shrinking or delicate materials issue) then the Borax really does super charge the detergent effects somehow.

I don’t doubt there might be something environmentally problematic with Borax but I just am not aware myself.