@Dirk, a good extension I use and which is a good complement for your ad and trackerblocker. It's called Site Bleacher it's remove by default all the crap from the pages you visit (cookies, local storages, IndexedDBs, service workers, cache storages, filesystems and webSQLs..), except from the whitelisted sites, all other you "had never visited".

https://github.com/wooque/site-bleacher

Don't forget to whitelist the sites where you want to log in.