I just purchased an old (circa 1900) farmhouse (2000 sq ft) in South Carolina which had used coal as the only heating source in every room. Every surface is coated with coal dust, which I would like to remove prior to beginning general re-hab of the house. The walls are original plaster lath(peeling paint), ceilings are painted wood bead board, floors are pine, all windows are original single pane with original glass.
I am considering a one time power washing, don't know what kind of chemicals to use, but I figure as long as I go easy on the plaster, it will all dry out in a few days and be done with it. I am open to any and all ideas. Every surface will be eventually painted or refinished, but I don't like the idea of sanding and plastering/varnishing over all that soot if not needed.