Installed v1.9 on Firefox 3.6.23 running on Ubuntu 10.04, but no icon or menu item appears anywhere, as far as I can determine. No mention anywhere in the description that it is incompatible with Linux systems or that it might require installation of additional support software.
Update: It does work on Linux when the instructions are followed, though it would be better if manual setup weren't needed. There are other cache cleaners and Firefox add-ons that place an icon or button in the GUI automatically.
I use this constantly. Be it a web dev or netadmin, Firefox aggressively caches and can make you crazy as you develop content or have a lot of DNS changes. This makes it so easy to just get things working again.