Instead of spare containers, you can use Temporary Containers: https://addons.mozilla.org/en-US/firefox/addon/temporary-containers/ https://addons.mozilla.org/e

Instead of spare containers, you can use Temporary Containers: https://addons.mozilla.org/en-US/firefox/addon/temporary-containers/ https://addons.mozilla.org/en-US/firefox/addon/temporary-con... This is like incognito mode on a container level.