Absterge and Facebook Timeline Cleaner Purge Your Facebook Activity
Chrome/Firefox: Facebook's privacy settings are, quite frankly, a mess. The only thing harder than figuring out what's being shared is deleting all of your activity. Fortunately, there are scripts to help with this.
As Business Insider points out, removing all of your Facebook activity can take hours. However, Absterge—a script that works in both Greasemonkey and Tampermonkey—can automate this process by deleting everything in your timeline. If you need a bit more nuanced control, Facebook Timeline Cleaner performs a similar task. Though, in testing, Business Insider found it was a little wonky to work with. Your mileage may vary.