I don't know if this will help you but when DD1 was a baby she had TERRIBLE diaper rash and it turned out to be a yeast infection. Nothing, and I mean nothing worked to help her. I kept trying and trying and eventually it was bleeding. The only thing that worked was some cream the Dr. gave me. It might be something to mention, good luck! I also use the California baby diaper spray, the reviews I read swore by it for rashes, but I haven't dealt with the rashes much. A little redness but it actually cleared up completely with the cloth! We use that Charlie's soap with ours.
I have been using reusable wipes for probably 5 weeks now. I was just keeping a small wetbag by the changing pad. I use cut up flannel blankets and some flannel I bought on sale. I LOVE them. They are faster than disposable ones and don't stink! I use Kissaluvs diaper potion (I think that's what it's called) in a peri-bottle full of water and some witch hazel. I have to shake it each time though, I think it might be easier to just use water but I like the smell.
As for using American products, I'd love to try some, but it costs an arm and a leg to import a lot of this stuff and isn't particularly green when I should be using local stuff. Plus I think the Germans have had their share of diaper rashes and MUST have something equivalent that works.
And tell me about this wet bag. I'm totally intrigued! How is it done??? I just have a stash of wash clothes next to the changing table and need to get a bowl of warm water for every time I need to change his diaper. This is also one of the reasons why we still mainly use disposable wipes. It's too darn inconvenient at 3 am. I do prefer using the wash cloths to clean - they work much better at getting the crap off his bum, but it's a PITA to get a fresh bowl of water all the time especially when I'm only half awake.