Junk items do disappear, however, they don't have to be in your vincinity.

Meaning, if you drop junk items just outside the walls of your main base, they will remain there forever.
If you however sail to the ocean and jump everything overboard, at some point they'll vanish. Good thing is you can't pick them up anyway.

If you're too impatient to wait for that, simply use the devcommand: "Removedrops" as it will erase everything you dropped at the ground. And when I say "everything", I mean everything, so be careful if / when to use it.


Thorin :)