Give old furniture a good cleaning

What's the best way to clean accumulated grime from old furniture? I don't want to damage the finish, which is still in good shape.
—Jeff Morris, Milwaukee

Start with soap and water, Jeff, and get more aggressive only as necessary. Mix a tablespoon of dishwashing liquid (it's not alkaline, like some household cleaners, and won't damage lacquer or shellac) in a quart of warm water. Stir it up to make suds, dip a piece of terrycloth into the suds only, and begin rubbing away the grime. You can increase the cleaning effect by dipping the cloth into the water, but don't let water stand on the wood; clean a small area, and then towel it dry. If stronger measures are required, moisten a cloth with naphtha, and rub. If you're still not satisfied, apply naphtha to a fine-grit scrubbing pad. To get into detailed areas with either soap or naphtha, use a nylon bristle brush, such as an old toothbrush.