A Natural Laundry Detergent that Works?

Just curious what is the best natural (chemical free) laundry detergent you have come across that still cleans clothing effectively? I've heard that white vinegar can damage machines (as in they should only be used in the rinse cycle) but it seems a lot of people use it. Other ideas? Castile soap, washing soda, borax, baking soda, etc?

I never heard that vinegar is bad for washing machines.

I have seen it mentioned every now and then to use in the rinse cycle to remove soap residue.

I have been using vinegar to wash my clothes for at least 5 years.

Maybe for the newer model of machines, it isn't good.  Mine is a 1993 Maytag.

Here are some threads on this subject that some folks might find interesting;

https://permies.com/t/234276/tech/Laundry-Hand-Matters-Laundry-Soap

https://permies.com/t/211598/permaculture-home-care-cleaning/Laundry-Soap-English-Ivy

https://permies.com/t/47399/laundry-soap

This thread might also offer suggestions of what other folks are using and getting PEP BB:

https://permies.com/wiki/108429/pep-nest/laundry-hand-PEP-BB-nest

I won't promise it is the "best" natural laundry detergent, but we've had success using a recipe containing a blend of Castille soap, washing soda, and borax with a few drops of essential oils mixed in. Honestly, I used that recipe because we had those ingredients on hand at the time, and it worked well, so we haven't bothered trying to change it. We have a relatively new (less than 5 years old) front loading LG washer/dryer combo. Not the fanciest option out there, but I'd consider it a modern laundry machine. Haven't noticed the soap causing any issues.

I have also seen vinegar recommended for removing residue in your laundry machine. We put a cup of white vinegar in the soap dispenser and run the clean cycle on our machine every month or two as well and haven't had any problems. I haven't used vinegar directly with clothes though. Not sure how that would turn out.