Does this stuff scratch? Is it plaster, a wood board product, or what? What are you trying to take the hard surface off of? If the surface is the actual plaster, the beige COULD be nicotine smoke stains, but you don't say what the "bad odor" smells like. If it is plaster, just wash it down with TSP (follow the directions) and prime it with binz or kilz, water or oil based, I prefer oil.
Post back with more info and we'll see what we can do.