@crazyfrank - the results presented by this plugin show all the book record entries in your library where within each group of entries there are duplicates found. You would never want to delete all the results returned, as then you would lose all of your copies of the book! The plugin can't decide for you which ones to remove, since you might have better metadata like a cover or whatever on one book record versus another one, so that is left up to you to decide.
The one exception to this is when doing a binary duplicate search, which you mention. In this circumstance, provided you check that extra delete binary formats option at the bottom of the plugin options screen, the plugin will make a decision for you and remove all but one copies of each book. Note that you will still be left with duplicate book records in calibre, which the plugin will still show you, and you still have to decide which of those to remove. However you don't have to worry about remembering which format on each book record was the duplicate. If the only format associated with a book was the binary duplicate that the plugin removed using this option, then you can just do a search for formats:false and remove those ones in bulk that way.