I just find that you can close notification on Clear Cache option, Open Menu - Add-ons - Extensions - Clear Cache - Options - Untick Show Notification Box - Save Preference.

Great little addon. Does what it should.
You can check its work if you enter
- about:cache
in the url-line. In all 3 Parts (memory, disk, appcache) everything cleared.
Only problem: F9 is now the (new) hotkey for this addon. Why not asking if i want it ? And why not a setting where i can change it easily ?
Btw, you can change all Hotkeys for addons at the addon-page, at the settings (icon).

Me ayuda

Hi I want ask is this working when use private browsing?

I used to always have to go to firefox settings to clear the cache when I was changing things on my website. That was frustrating when I made small changes. This is a lifesaver.

It's great