I opened a topic on KDE forum about adding a trash for every drives: https://forum.kde.org/viewtopic.php?f=223&t=130133
To summarize :
As you know there is no trash for the removable drives, there is only one for the system. At the moment you only have 2 "bad" solutions for emptying the removable drive trash. Either you emptying the whole system trash, but you not necessarily want to do this because you may have some deleted files from your HDD that you are not ready to completely delete, either you display the hidden files and delete the .Trash-1000 folder on the removable drives, but that's not really user friendly.
So the new feature I propose is simply to have a trash for every drive ! We should display a trash for every removable drives in Dolphin. After all each media have its own .Trash-1000 folder.
That will also help people that are switching to Linux on Plasma desktop. They often don't understand why their USB stick become full whereas there is only some little files or no file at all on it. But if they see a trash that correspond to their USB stick they will understand than they can retrieve their files and empty the trash.
I have made the same request to Gnome and there is some useful info there
*** This bug has been marked as a duplicate of bug 76380 ***
I don't think it's a duplicate of bug 76380. What I mean here is to have the possibility to empty the trash of a device without emptying every device trash. It surely need bug 76380 to be fixed first.
(In reply to Nate Graham from comment #2)
> *** This bug has been marked as a duplicate of bug 76380 ***
Please stop marking bugs as duplicate of the bug that is never going to be fixed.
This 76380 is regressing for 15 years across years and looks like it will not be ever fixed.