Be aware that eliminating browser history will also eliminate use of app-tabs. You can't use private browsing because that would prevent you from recording new form data (and use of app-tabs). You can eliminate recent browsing which is what you asked for by sorting History in the History sidebar by last visited and deleting recent browsing history there, or delete history selectively based on searching within the library list where you have the same search facilities but have additional columns that you can check. For more information on selecting and deleting history, see * http://kb.mozillazine.org/Viewing_the_browsing_history_-_Firefox