Rated 3 out of 5 stars
It works...? I don't understand why the Form & Search History is a gray box. If this is not being erased, it's not doing everything.This review is for a previous version of the add-on (220.127.116.11-signed.1-signed).
It's because there is nothing to erase. That is built-in feature of Firefox, nothing to do with this extension.