About six months ago I made the liquid homemade version of laundry detergent... and it lasted that long. It worked great, was super cheap, easy to make and I have no complaints about it, but I wanted to try the homemade powdered version as well and see if it worked comparably.
As for ease of preparation, it was incredibly simple. The ratio is like this:
1 bar soap :1 cup Borax : 1 cup washing soda
Many people suggest Fels Naptha, Zote, Ivory or Dove soap. I doubled the recipe and used one Fels Naptha and one Ivory. (The Ivory gave it a great smell.) I have some friends who save the little pieces of soap from the bath/shower and combine those in the mixture.
The soap needs to be grated, and that's as difficult as it gets.
You'll want something with a good seal and a wide lid to keep it in. I mixed mine in a recycled plastic container that was also really good for storing the detergent.
To use, scoop one tablespoon for a regular load and 2 tablespoons for a large or heavily soiled load. It washes just as well as store bought detergent.
I think the benefits of the dry version are how simple it is to make and store. I think the liquid version goes further, but we'll see how long this one lasts.
Have you tried either version? Do you have a preference?