This is an extremely simple Chrome extension which lets you delete history using a specific site or keyword. By default, the Chrome history UI only shows you one page of results at a time, and you have to manually keep deleting all the results. This extension automatically deletes history in batches of 100 (max allowed by Chrome search) until there are no results left. This extension is completely open source and is less than 100 lines of code: https://github.com/raoneel/history_deleter