You could certainly also try this site PolyAmoryWorld.com. There are some profiles from polyamours people not only from around the world, but also from Germany.
Most of them are from the Netherlands but live close to border. Definitively worth a try!
Hi there, I would like to showcase your site on ours in the spirit of collaboration. Have already done polyamory world. Do you have a little sales pitch for me? Tx!