I have already gone through How do I completely uninstall Google Chrome and Chromium? and I'm really not getting why the solutions given there are not working for me.
What I'm doing is:
sudo apt-get purge chromium-browser rm -rf ~/.config/chromium
Then reinstalling by running the following command:
sudo apt-get install chromium-browser
This must remove the settings of chromium-browser and do a fresh installation. The browser is uninstalling, but after being installed it is containing the previous settings, moreover it's not signing me out of even Gmail!