Yeah that´s right. I thought it would be nice to have one article for both extensions because they work rather similar. Stealther temporarily disables the following settings in firefox: Browser History, Cookies, Downloaded Files History, Disk Cache, Saved Form Information and Sending Referrer Header.
Distrust, the second extension has similar features: Disable (SSL) Cache, Set the cookies to live until the end of the session, Clean up the history from item that were added after it was activated and Clean up the downloaded items, from the download manager, that were added after it was activated.
Seems to be enough to run one extension, both have more or less the same functionality.

Erase Personal Tracks with Disk Cleaner
5 Essential Firefox Extensions
10 Essential Firefox Extensions for 1.5b2