As a developer, Safari presents some issues when trying to test logins and new content. Safari simply doesn’t like to let go of Cookies and History when you use the built-in buttons to do just that. Build a simple app on your target computer to do this for you quickly, so you can get back to your development and testing. Simply put, just use Apple Automator to create a simple Mac App to delete the necessary files to cleanse Safari Cookies, History and whatever else you are irritated by. This is a workflow that Quits Safari then moves the files I need to cleanse to the Trash and Empties The Trash. It then re-launches Safari so I can continue here I left off, with a blank screen. The caveat is that this will remove ALL cookies and history and whatever you add to the Get Specified Finder Items list!! Your bank logins and similar tracked authentication will disappear too and you will need to login again. This will not remove bookmarks or password program records, unless you specifically add those to the Finder list.