Best way to remove years old milk stains?

Hi all! I’m wondering if there’s a stripping-type or batch method to helping get out years old breastmilk and/or formula stains. A lot of the clothes have stains like the picture and being 8 months pregnant i’d super love to NOT scrub each individual onsie with dish soap. (seems to be the top recommended) I have stripped blankets, sheets, and towels in the past so I have Borax and washing soda. I’m wondering if that would help or if anyone else has any other recommendations. :)

Hi all! I’m wondering if there’s a stripping-type or batch method to helping get out years old breastmilk and/or formula stains. A lot of the clothes have stains like the picture and being 8 months pregnant i’d super love to NOT scrub each individual onsie with dish soap. (seems to be the top recommended) I have stripped blankets, sheets, and towels in the past so I have Borax and washing soda. I’m wondering if that would help or if anyone else has any other recommendations. :)