how to delete a single item from trash forever in mac os x

"Open a terminal window and type in ""rm "" (without the quotes, but with a space at the end).

Open the trash and drag the file you want to delete onto the terminal window. The file path will appear.

Press return in the terminal window to delete the file.

You can remove multiple items
by highlighting the trash item and scroll down as many items as you want removed, hold shift key and highlight last item and all items in between will be highlighted. Drag over to terminal, as above, and all will be deleted.

works for me on 10.6.8"

You have a problem with a simple enough solution: Restore all three of them, then put the two that you don't want back in the trash.