I only use baking soda in the wash (1 box) in the rinse water-2nd and Final rinse for multiple rinse cycles washing machines . I also use Arm & Hammer Detergent for Sensitive Skin for washing clothes to not only clean, but soften fabrics & my clothes and quilts. For very hard water or very soiled clothing items, I add
20 Mule Team Borax to the wash cycle
https://www.20muleteamlaundry.com/. My parents and grandparents have been using these products since the early 20th century as I still do. I know that many modern quilters might sneer at these products, but they really do work wonders!
You will find it at most grocers. If not, look for them online like most everything else.