RJMailloux wrote: ... I understand the term "French Polish" applies to the type of finish applied to a guitar...
French polish is not a type of finish. It is a technique on how to apply shellac (a natural resin derived from the Lac bug cocoons) to a surface. The finish type is called shellac (or goma laca in Spain and Mexico).
There are many ways to apply this shellac. One of those is French polish. After filling the pores and sealing the wood (pores filled with pumice and sealing with a lower concentration of dissolved shellac), shellac previously dissolved in alcohol (pure ethanol) is rubbed with a muneca (a little ball made of cotton with probably wool inside to absorve and retain the shellac). Oil (preferable olive oil) is used to help move the muneca around. There are several steps to it. The process is simple, but hard to do well until you have gained some experience.
One of the main troublesome results is uneven surfaces. That is the reason a very fine grit sandpaper (wet-dry 600 or higher) must be used between (one or several) layers to make sure the surface is even. Shellac is not the greatest finish to provide strenght or protection against dings, bumps, water, or so. It protects way less than lacquer. However, many people says that it keeps the sound unaffected. With the advent of new lacquers, it seems that that could be no longer the case. The Milburn tutorial is the effort of several people to provide a uniform way of doing French polish. I learned a different way. However, since I learned about it, I have used it with excellent results.