How can I flush /delete the Finder clipboard in OS X 10.8.3 ? I always see 2 items when I paste from the clipboard
Try execute command: pbcopy &lt;/dev/null.

pbcopy and pbpaste are two commands that provide access to clipboard.
pbcopy will copy a string to the clipboard (overwriting the original content).

In this case you are copying an empty file. Since you can't pass a file but a string only, this "&lt;" (a redirection) will redirect the file content to the pbcopy arguments.