Great addon!

Note: it uses RegEx and so make sure to "escape" special characters when needed. For example search?q needs to be written as search\?q

edit: I wish there was a way to similarly clean the files cookies.sqlite(-wal/-shm), permissions.sqlite, content-prefs.sqlite, since they can also document the sites/pages you visit. Currently I'm managing this by using a batch file that replaces those files with an early copy of those files (that only include the specific sites I'd like to keep the data of)