Kann ich dieses Produkt für diese Art von Dusche verwenden? (Ich bin besorgt, dass das Material in den Duschrohren aus Kunststoff und das Produkt zu abrasiv ist).

I did it once before and it worked well and pumping is still good months later. Am not a plumber though

If it helps: there are only a few kind of acids that can break down plastic. You should be fine in using it but please read the instructions and follow them carefully

I would suggest you don’t use it. Inform your landlord that the pipe is clogged. The blockade could well be in the main pipeor further along your branch pipe, then a professional pipe cleaner would have to come. The chemical cleaner will just sit in the P-Trap and will do something between „nothing“ and „making lots of foam and funny noises“ but no working results.

It’s not going to affect plastic, think about it, it’s in a plastic bottle. I’d be more concerned that it affects metal. But if they sell it as drain cleaner, it’s not going to damage your drain pipes.