Restoring Wooden Furniture
If a commercial cleaner/conditioner doesn't do the job, remove the built-up grime with a mild solution of warm water and liquid detergent. Use sparingly and work quickly; don't soak the piece of furniture or pour the solution over it. Water can cause a white haze to appear on a shellac or lacquer finish, the same haze that appears when a glass leaves a white ring on a table. When the furniture is clean, rinse off the detergent with water and then carefully and thoroughly dry the wood with a soft cloth or a towel.
Let the wood dry completely. If there's a haze on the finish, you may be able to remove it with steel wool. Buff the surface lightly, with the grain of the wood, with No. 0000 steel wool. Then apply a commercial cleaner/conditioner and lightly buff the wood again.