Installing water pipes with flexible hoses

I would be very grateful if the next answers relate to my question.

Welcome to the Internet! You neither get the answer you hoped for nor will the answer fit the question! (A Usenet wisdom which also applies in the forums of the www.)

What do you think about the construction, can it work the way I imagine?

I don't see anything against it. Is there a wall breakthrough? Is the neighboring room heated and ventilated (humid air from the bathroom)?

Instead of hemp, I recommend Teflon sealing tape, which is much more pleasant to handle for laymen (I am one, you maybe not). IMHO.

Super thanks a lot for your answers teflon tape sounds great I will use it like that :) yes I made holes with a 24mm drill so no moisture will be transmitted, as I want to fill the holes again.