I had an eye-opening experience a coupla months ago, just after we moved into our new house. Our new laundry facility empties the dirty wash water(and rinse) into a large utility sink. I had run out of Charlie's soap, and was using a small box of soap that was left in the house. The directions said to use the measuring cup in the box, which was like a regular CUP. I used two of the little tiny Charlie's Soap scoops(like a tablespoon), with a dash of Calgon water softener. I was present when the rinse water began to empty into the utility sink. After only using 2 Tbsp of detergent, there was still bubbles in the rinse water!!
Want to use less laundry soap, use one eighth of the amount they tell you! Suffering from itchy skin?? Decrease the amount of laundry soap you use. They probably just tell you that so you use it more and have to buy more frequently!! That box still has soap powder in it, and there was only about 2 cups when I started. Imagine if it was a bargain box of Arm and Hammer?? Buy it about once a year??