You can make your choice permanent or temporary by clicking the plugin icon on the tab bar. Note that even if you uninstall the add-on your preference settings will not change.
Click to Play Switch: Another add-on that adds a button to Firefox’s address bar to toggle the Click-to-Play on and off. You can toggle the setting on or off by clicking this button. It’ll reload the page automatically to make the changes. This extension is useful in certain situations, for example, when your settings blocks plugins, sometimes it’ll break the page functionality. You can disable the settings and reload the page by clicking this button. When you restart Firefox, the extension sets the preference to true again so you stay protected.
The value of Click-to-Play Feature: Flash, Java and PDF are most insecure browser plug-ins, but unfortunately, they are necessary in some situations. If you have no control over them, there are chances for malware infection via these plug-ins, especially when you surfing through shady websites. Click-to-Play lets you make plugins optional in websites. You can enable this feature on trusted sites and block temporarily or permanently on all other sites.