Previously we published a tutorial on how to remove add-on leftovers from Firefox manually. That was a little difficult process for some users, as they want to identify each add-on’s entries manually. Here is an add-on called “eCleaner” to make things a lot easier. eCleaner is designed to quickly and easily remove preferences left by extensions after uninstallation and help you speed-up your Firefox start-up.
How to use eCleaner?
Install the eCleaner add-on from Firefox’s add-on repository. After installation, restart Firefox and navigate to Tools – Add-on to open Add-ons Manager (or use shortcut key Ctrl + Shift +A).
Locate eCleaner add-on and click the “Options” Button. Select add-on entries that you haven’t installed from the list (use Ctrl + Left mouse click to choose multiple entries) and click “Clear Selected”.(Source)
