I think the woodwork in our 1918 Craftsman cottage was shellaced when first built. It now has turned almost black. We have tried stripper, solvents and varnish remover. Nothing touches it. We want it off. Looks like the original wood is burlwood. One show I saw with Bob was restoring Frank LLoyd Wright house he lived in. Bob talked to a guy removing shellac with some product that made it come off like water. WHAT WAS IT?