White knuckling is more an AA term. It's someone holding on for dear life so they don't drink or use.
AVRT is not a method that prescribes to this term since its not part of the big plan. In fact any conversations with my AV is not even something I entertain. So white knuckling would be like me going back and forth with AV and me ultimately not on the winning side of the debate.
Hope that helps.... This is just my thoughts... Others may have different ideas.
K