Hello, it's me, Brenda. You guys make me think I should go back and get a chemistry degree so I can really answer everything.
(I'm not a regular on any boards, so I don't come back and check things here. I got some private emails, so I thought I'd pop back in here.)
1. Homemade detergent: That's actually what I was trying to mimic. That's what I used before I started cloth diapering, and since real soap is not to be used on cloth diapers (it leaves a waxy coating that's not as difficult to remove as the industrial additives, but it does stay on there) I wanted another "recipe" that left out the soap. But what did the soap do? What needed to replace it? After talking to other chemists and textile people, that recipe seemed to have all the basics it needed. I tried it for 6 months before recommending it. But this is meant to be a more diaper-friendly *replacement* for that home-made formula. And easier to make, frankly!
2. Front loaders: I'm depending on people with front loaders to report back. I'm still in the top loading age. I was afraid the simple green would be too sudsy for FL, but the two people I've heard from so far said it went okay. I'd cut the amounts in the same proportion that you normally cut other detergent amounts. I'd like to hear from front loader users, though.
3. Simple green: full strength or diluted? Full strength. I never understood why they put it in a spray bottle if it was meant to be diluted! But I use it straight from the full strength spray bottle and put about 4 sprays in.
4. The brand of Washing Soda doesn't matter. It's all sodium carbonate. But Arm&Hammer is usually what you see. You can even buy sodium carbonate in bulk, $10 for 10lb, from thechemistrystore.com, but I honestly don't know if it's worth it after shipping. (you can also buy sodium percarbonate in bulk there, which is oxyclean, but again I don't know if you come out ahead after shipping.)
5. Hard water/soft water is something I know very very little about. I do know that Washing Soda acts as a mild water softener, which is why it's used in most detergents. But how this will work in soft water vs hard water I'm not certain. For the record I have city water, which I assume is soft.
6. I use this on my regular laundry, too. I have a sample that Charlie's sent me long ago, and a bucket of Sam's club, and I can't tell the difference when I use one or the other or my own recipe. I'm sure something like sensi-clean or Charlie's or Allen's Naturally is better since it was formulated by chemists who know what they are doing, but this does seem to work, even if you only have it as a back-up for when you're waiting on your other stuff to come in. For the record, Charlie's may come out to cost not much more, as one person pointed out in a private email. You get 80 washes for $12, and that includes shipping.
If you have any questions, don't hesitate to send me a private message. I don't return here much, and I'll answer those quickly.