I do mine just like they said. I use Flex Coat but have heard a lot of people liking Prokote. As far as thread size, you may want to start with a little larger diameter of thread (D) at first and then work your way down towards an "A".
If you do use Flexcoat/ Prokote you will need to buy or make a call turning jig. These finishes dry extremely slow and will need to be turned slowly for a few hours or the finish will sag.