Cleaning Products: #1 laundry detergent

I try to use as few chemicals in my home as possible. This includes in my laundry room. I have been using home made laundry detergent for about 8 months now and love it. I also don't use fabric softener, but vinegar instead. I started that when I was cloth diapering Austin, as fabric softeners make it harder for materials to absorb water. This goes for towels too.

The laundry detergent recipe that I've been using is from the Duggar family recipes. It's about the 3rd recipe down. It uses a bar of Fels Naptha soap

1 cup of washing soda (not baking soda)

and 1/2 cup of Borax.

And it makes 10 GALLONS of laundry detergent! Since I have a HE front loading machine, I use about 1/4 cup per load, sometimes a little more, sometimes a little less. I do about a load of laundry or two a day, and the first batch that my mother-in-law was kind enough to make for me lasted me 6 months. I recently had to make another batch. It was super easy. I used a food processor to grate the soap, and the rest was simple!
Finding the ingredients was a bit of a challenge the first time. I've heard that Wal-mart carries washing soda, but I have yet to be in a store that acutally does. Strangely enough, I found that Ace Hardware actually carries all the ingredients, though the store might have to order it, or you can order it online and have it shipped to the store. That way you don't have to pay shipping and handling. Last time I ordered, I got a whole box of Fels Naptha and a crate of 12 washing sodas. Borax I've never had a hard time finding, so I didn't stock up on that.
I have heard that there are "kits" on ebay that will sell you just the ingredients in the amount that you need to make your own. These kits run about $7.50 and make about 5 gallons. Even if you used on of these kits rather than getting the seperate ingredients yourself, that would be about $1.50 per gallon. How does that compare with what you're buying at the store? When I buy the ingredients seperately, I know it's cheaper than that. One bar of Fels Naptha is about $1.30, a 3 1/2 pound box of washing soda is $3.80 and a box almost 4 pounds of Borax is about $6.00. Again, I only need a cup of washing soda and 1/2 cup of Borax. I'm probably spending less than $2.50 for 10 gallons of detergent, so about $0.25 a gallon.
I also have more control of what I put in the detergent. Let's go over the ingredients.
Borax is a naturally accuring mineral, a salt. There is some need for caution with this in your home. While "It is not accutely toxic...a significant dose of the chemical [can]cause sever symptoms or death."
Washing Soda is a sodium salt and is used regularly as a water softener. It can be extracted from the ashes of many plants. It's actually used in cooking, including the dorm room favorite, Ramen Noodles. It is non-toxic.
Fels Naptha soap, there are some concerns about this soap as it it can cause eye and skin irritation. I looked at the Material Safety Data Sheet, or MSDS, which stated that it did not have a significant environmental effect. It also states that there are no known chronic health effects. But I may start looking for a homemade lye soap to use instead.
If I want a scented detergent, I could add essential oil to the mix. I don't since I'm doing kid and baby laundry. But the ability to control what you put in your detergent is comforting to me.