If you find yourself just turning this extension off or undoing the edits to your host file, you should try http://selfcontrolapp.com/ for OSX, which blocks URLs for a specified period of time without the ability to unblock them. It is open source, so in theory you could presumably go source diving to find a way around it, but that would take more effort and focus than doing whatever you are supposed to be doing.

Also, if you find yourself desperately needing this, consider the possibility that you may want to get more/regular sleep, exercise, and better food. "Sleep is for the weak" is a load of horseshit. Your brain is a part of your body and you should take care of both. This got me through the last parts of undergrad and I am very grateful to the maintainers, but I wish I'd not needed it.

EDIT: there is apparently an app http://getcoldturkey.com/ for windows. I've never tried it though.

Also, Momentum for Chrome is a good replacement for the "recent pages" new tab screen: https://chrome.google.com/webstore/detail/momentum/laookkfkn...