Using different DNS or encrypted DNS wouldn't help if that government very serious to perform censorship though. They'd just obtain list of IP owned by Twitter and ask ISP to block connection to those IP.
What do you mean by serious censorship? Are you referring to transparent DNS? As far as I understood it, encrypting your DNS (and changing it to other resolvers, not the one provided by our ISP) should allow us to hide the request to the website that we want to access. I've been using DNScrypt and it works fine to encrypt my DNS request, so I can visit blocked websites just fine.