Let me start by saying that the single most important component of your arsenal of laundry tools is your water. Like with many things if you start with bad water your final product isn't going to be good either. I've lived places where we had great water. Just about anything I did gave me clean diapers. All the usual soaps worked, the free and clear, Charlie's, specialty soaps like rock'n green; it all just worked. Now I live in an area where the water is very hard but not with the traditional dissolved metals. In most areas calcium and magnesium make up the deposits that form on faucets and taps that are indicative of hard water. Whatever is in my water here doesn't do that. It just makes it impossible for most soaps to get diapers clean.
The free and clear of all varieties failed to clean the diapers. Charlies (borax) built up in the micro fiber diapers and made them water proof (not repellent but quite literally water proof). Regular old Tide powder wouldn't dissolve. The list went on and on. Finally we tried biokleen They make bacout which is a spray that seemed to help with smell issues we were having. So in order to deal with our really bad water a system was developed. First a soak cycle a full load worth of biokleen. This is followed by a full wash cycle. In that cycle a downy ball filled to the bottom line with white vinegar is added. An extra rinse is employed to get rid of the vinegar smell.
It was a very frustrating experience that when we moved our old system for cleaning diapers failed so miserably and so quickly. The mad rush of experimentation was frustrating. Finding the solution was such a relief. In the end it was worth it. So remember when you are online looking at reviews of soaps to use to clean your diapers. The water is the most important ingredient in your laundry. Your water dictates how you have to clean your diapers. So find something that works for you, your baby, and your water; use it. And who cares what the review sites say. As long as you get clean diapers that absorb water and that don't irritate your child's skin you've won the laundry game. Sit back, relax, and enjoy your victory!