Bottom line, I think the type of water you have - how soft or hard - will determine a lot as to what will work for you when it comes to the homemade stuff. Also, different things work well for different dishwashers. So there are some variables to work out. Not everything will work the same for everyone.
One combination of ingredients that I was seeing posted quite frequently was Borax, Washing Soda, Kosher salt and Citric Acid. I don't want to use Borax, and citric acid seems too expensive from what I could find.
I started searching for recipes that are Borax-free. I found one that I wanted to try and used it for about a week: Natural Homemade Dishwasher Detergent. Ingredients: water, vinegar, liquid castile soap, pure lemon juice, salt and washing soda.
I loved it for about 3 or 4 days, until my glasses all started coming out cloudy. So I kept searching for another one that didn't contain Borax or citric acid, and didn't have too high of a proportion of castile soap (making it too expensive).
Then I remembered a blog post I had bookmarked a while ago that had very useful information in it. 10 Things You Should Know Before Making Homemade Dishwasher Detergent. She concludes that you may only need washing soda to wash your dishes, or maybe also add a little soap.
So I thought about all I had read and learned (including using less soap to get better results), and I tried a combination using my best educated guess: 1 tablespoon washing soda and 1 teaspoon castile soap. I also used vinegar as my rinse aid (see below for more on that). Everything came out perfect and sparkly clean! I continued it for a few days getting nearly perfect results every time.
I wasn't sure if it was the castile soap or vinegar (or both) that was doing such a great job, so for about 2 weeks I experimented with each load (I kept the washing soda constant because I knew I wanted to use that as my base). I tried varying amounts of vinegar and castile soap, even leaving each of them out completely.
What I found out was that I definitely needed the vinegar to rinse all the food particles away and get all the glasses shiny and clean. I thought that I might get away with not needing the castile soap, but without it, I have had several things come out with food stuck to them. So, looks like I need both in addition to the washing soda.
So here's what I'm using in my dishwasher:
So I thought about all I had read and learned (including using less soap to get better results), and I tried a combination using my best educated guess: 1 tablespoon washing soda and 1 teaspoon castile soap. I also used vinegar as my rinse aid (see below for more on that). Everything came out perfect and sparkly clean! I continued it for a few days getting nearly perfect results every time.
I wasn't sure if it was the castile soap or vinegar (or both) that was doing such a great job, so for about 2 weeks I experimented with each load (I kept the washing soda constant because I knew I wanted to use that as my base). I tried varying amounts of vinegar and castile soap, even leaving each of them out completely.
What I found out was that I definitely needed the vinegar to rinse all the food particles away and get all the glasses shiny and clean. I thought that I might get away with not needing the castile soap, but without it, I have had several things come out with food stuck to them. So, looks like I need both in addition to the washing soda.
So here's what I'm using in my dishwasher:
1 Tablespoon washing soda
1/2 teaspoon castile soap
1/4 cup vinegar as the rinse aid
Simple and toxic free :)
(I still might get one or two things that come out dirty, but that usually happened with the store-bought stuff too. Overall, I am very happy with these results)
***
Rinse Aid
We had been using Jet Dry for quite some time, but obviously we wanted to ditch that too. I have read all over the place to use vinegar as a rinse aid.
HOWEVER, most people suggest putting it into the rinse aid compartment. I read on a blog post that "the acid in the vinegar can damage the rubber components in the rinse aid compartment." And that came straight from the dishwasher repairman.
So an alternative is to use a small bowl that can sit right-side-up in the top rack and put some white vinegar in it. This will slowly slosh it around as it goes through the cycle.
And as I said above, this is working very well for me.
***
Cost comparison
I wanted to see where my three ingredients fit into the spectrum of store-bought detergents. Here's what I calculated, listing the least expensive first:
Great Value (Walmart brand) powder detergent, 75oz box
$3.22 (price from their website) / $.04 per ounce
My homemade option
Washing soda + soap + vinegar = 2.13oz per load = $.11 per load
$.05 per ounce
Cascade powder detergent, 75oz box
$6.90 (priced from Walmart's website) / $.09 per ounce
Seventh Generation (all natural) powder detergent, 75oz box
$7.49 (priced from amazon, shipping not included) / $.10 per ounce
I may not have beaten Walmart in price (who can?), but I'm sure I beat them in safety of ingredients (they don't even disclose their ingredient list...what are they hiding?).