On https://community.bistudio.com/wiki/removeAllAssignedItems it says:
"Unassigns and deletes all linked items from inventory (map, compass, headgear, goggles etc.)."
But apparently it doesn't remove headgear and goggles, I had to use two more commands (removeGoggles & removeHeadgear).
I could fix that wiki entry myself but I cannot register for some reason.