I think the vinegar comment was from me. Actually, I don’t use it at all....anymore. My family had a genetic skin disease that left some of us very sensitive. I didn’t inherit, so I was lucky. In answer to your question, we used vinegar in the machine for nearly 20 years. It (the machine), lasted for more than that, but it died from other causes. Actually, you don’t need that much vinegar to accomplish the removal of soap from your clothes. Just enough to shift the pH slightly is enough. It really left no odor in the clothing.
In the manufacture of soaps, one introduces an alkali to precipitate the soap from the solution. In the case of cheap white vinegar (acetic acid), one is doing the opposite. You’re simply putting the precipitated soap back into solution. Of course, if you have normally acidic water, it might not even be necessary. It is worth a try for those that have a problem with “touchy” skin.
Thank you!