Not a perfect solution to this scenario, but I have used multiple Firefox profiles in the past this way. The profiles are isolated at the file-system level, so extensions remain separate. So you could have a 'hardened' profile will all the blocking/cleaning extensions, and a 'trusted' profile with no extensions. Profile isolation also covers configuration, so you could even tweak those independently.

I've experimented with that from time to time, but it hasn't stuck. The problem is when I click through. Container tabs handles that, but I would have to be extremely vigilant to prevent sites from loading outside of the hardened profile.