The Firefox 85 version is scheduled to include an option that would allow users to remove the "Other Bookmarks" button, but this is not available yet for Firefox 84.x users.

The CyberNet tech blog digs into Smart Bookmarks, one of the neatest new features in the upcoming Firefox 3, and pulls out a how-to guide to compiling your own iTunes-like collections. Using a ...

You can clear your history on Firefox manually, or set it to clear automatically whenever you close Firefox.