I have the same problem with the error :
"You can't copy the item "" because its name is too long or includes characters that are invalid on the destination volume." when try to empty my trash in secure way.
Here is the solution step by step:
01. Go to the Link :
02. Download the "trash-it"
03. Unzip it, Enter into the folder, go to "Drag content to Desktop" folder and double click to the "Trash It!.app"
04. Press "Really Stuck"
05. See your Trash, the undeletable folder/files is gone from your trash