I have been using this since October 2008 with no issues. I've actually received compliments on used diapers that I have sold smelling so good and asking what I used :)
If you're looking for the clothing version of this, look here.
Here's what I do. It's cheap and I love it :)
More or less, It's: (this is not exact, since I use the larger recipe below)
1 cup washing soda
1 cup borax
1/2 cup of oxiclean
BUT.... I don't like having misc. leftovers, so I make up a batch... like this :)
It should cost $30, max.
3 Boxes Arm & Hammer Washing Soda (55 oz each)
2 Boxes 20 Mule Team Borax (76 oz each)
1 Large Tub OxiClean (96 oz)
Yes, it's a lot, but it's super cheap to make, so no biggie :) It just lasts forever. Or you can share :)
**I'd like to make a note about the borax used in this recipe. A recent article by EWG cautions the use of borax for cleaning in the home noting that toddlers and young children face special risks from hand-to-mouth transfer of carpet or crack and crevice, dust or spray borax treatments. I would recommend not using borax as a general home cleaner - any cleaner (aside from pure water) used for these purposes will leave a residue. I feel comfortable using the minuscule amount in the detergent. It is not used on open surfaces and is washed out during the rinse cycle.
You can read a bit more on this debate here - there are some great points of view in the comments.
**I see a lot of people asking where to purchase these supplies. If you are unable to find them locally (I've had great luck at our grocery store and others at hardware stores.) you can purchase everything to make this on Alice.com at reasonable prices and that includes free shipping. They currently do not carry the 96 oz Oxiclean, so you would want to purchase two of the 56 oz that they offer.
This is my current wash routine:
I love this routine. My diapers have no smell and are so fresh. I have also been using an open pail (pail w/ no lid) and that seems to make such a huge difference when it comes to ammonia lingering.
Warm wash with cold rinse w/ 1 tablespoon of detergent
Hot (or warm) wash with cold rinse w/ 1 tablespoon of detergent
I have also done this in the past with good results:
Cold wash/rinse w/ 1 tablespoon of detergent
Hot wash/rinse w/ 1 tablespoon of detergent
If you are dealing with ammonia you can also add about 1/4 to 1/2 cup of vinegar to your hot wash http://www.theecofriendlyfamily.com/2009/08/cloth-diaper-detergent.html