I once researched historic whitewash because it was used routinely on outbuildings on the plantations and historic town houses here in Alabama. (I was curator of a historic property here). traditionally even the White House in Washington was whitewashed every few years. The recipe I found was essentially the limewash as given in your homestead link. Another finish for old wooden buildings was copper sulfate mixed with motor oil or sometimes linseed oil. This creates a dark greenish stain--preserves wood, but used motor oil is a pretty serious carcinogen.
