[fest]

Google is really not helpful in finding out what the nut-retapping trick is :>

Do you mean cutting the screw to length with a nut on it, which then fixes the thread as you unfasten it?

[gtvwill]

This works well. I would suggest acquiring a triangle file and a blade file. You can fix cut thread ends easy and even some cross threaded sections.

You don't always have nuts to go on threads items. E.g. when a rod is threading into a block.