No, you should always use "Clear Recent History" to clear the history yourself. You can consider to use Private Browsing mode to open web pages when you are on a computer that is not your own.

• https://support.mozilla.org/kb/remove-recent-browsing-search-and-download-history

Oké, dank je, maar ik doel met name op zaken die niet tot recente geschiedenis worden gerekend, zoals bladwijzers en door Firefox voor mij bewaarde inloggegevens. Die staan, neem ik aan, in een door Sync aangemaakte map, gekoppeld aan mijn account. Hoe verwijder ik, of hoe verwijdert Firefox die gegevens van die tijdelijk gesynchroniseerde computer?

You should never connect to Sync when you are on a public computer. You would have to remove the Firefox profile folder manually by using the button on the "Help > Troubleshooting Information" (about:support) page and possibly also the location for the disk cache as found on the about:cache page to remove your personal data from that session.

If you need to access bookmarks then export the bookmarks to an HTML file and either copy the file to an USB stick or on a file hosting service of internet or on personal web space that your ISP provides to you.

You can also use the Profile Manager to remove the profile.

• https://support.mozilla.org/kb/Managing+profiles