Given that beliefs are established on our brains I'm less and less sure whether "If a belief turns deadbeat, evict it. " is meaningful advice.

Most people can't just make a decision to change one of their beliefs. People can quite easily switch the answer they give to a question but they can't as easily change the belief on a deeper level.

Akrasia happens when your rational understanding of a situation differs from your emotional one. When a person isn't willing to admit to himself that he believes A it's very hard to debug and remove A from the brain.