What would be a quick custom command to do that?
I believe this removes everything including the directory itself I'm right-clicking on:
test "!?Do you really want to delete ?no!" == "yes" && rm -rf !&
...but it would be great if I didn't have to delete and re-create the directory (since WinSCP doesn't automatically create it, when I delete a file and a /tmp directory is not present).
Wish-thinking, it would also be great to have a conditional command where the "Empty trash" appears only when I right click on my trash folder.