I've had real good luck with Selectol Soft, sometimes in conjunction with water-bath developing as detailed above, to reduce contrast by a paper grade or more. More often, I use Selectol Soft in tandem with another harder-working developer (e.g., Dektol) to get intermediate contrast on graded paper. This was a more common practice before VC papers became mainstream.
The Moersch Separol Soft will work like Selectol Soft in this regard and may be easier to find in Germany. You can mix your own as well using David's formula or just Google for Ansco 120 or Selectol Soft substitute.
Flashing is a useful tool, but reduces highlight contrast in the process. This is often desirable, but sometimes not. All three tools together can squeeze a lot of contrast on to grade 2 paper.
One more technique to reduce contrast is selective latent image bleaching, or SLIMT. The basics for reducing print contrast are outlined here:
http://unblinkingeye.com/Articles/LatentImageBleach/latentimagebleach.html and on David Kachel's site here:
http://www.davidkachel.com/assets/nw_strry.htm
That should be more than enough to get you going.
Best,
Doremus