I use a separate vault for items I do not use anymore but want to keep.
In my main vault I choose an unwanted item, then "right-click" -> Share -> "Müll" (my own trash vault called "Müll") -> Move.
But the item lands in thrash of the main vault.
I assume it is a bug ...
1Password Version: 6.8.7
Extension Version: Not Provided
OS Version: MacOS 10.13.3
Sync Type: Not Provided