Vinegar is a great rinsing and softening agents that helps prevent soap build up and hence, the yellow dingies. Fun fact of the day - laundry bluing, made of blue iron either solid or suspended in water, came into use to counteract the yellow color of soap buildup. It came into commercial use in the Victorian era and continues today. When you add bluing, the clothes aren't any cleaner, but they look whiter.
Back to vinegar. Have no worries that your clothes will end up smelling like a Greek salad if you use vinegar in your rinse cycle. I use also pour a good slug into my dishwasher every time I use it - probably about a quarter cup. No more white slime on my dishes since phosphates were outlawed in automatic dishwasher and laundry detergents. Glasses come out sparkling, spot-free, and there's no residual odor. Great stuff, vinegar!
I ended up making liquid laundry soap because it's so humid here in southeast Texas that the dry stuff turns into cement in a couple of days. It doesn't matter how tightly sealed the container is either. I even tried storing it in a Mason jar and sucking the air out with my vacuum sealer. That kept it dry for a few more days, but eventually - you guessed it - cement. Plus, it's a pain to have to re-seal it every time I wash a load. I just looked back at what I wrote and thought, "Ouch! First-world problems."
