How to clean black, inlayed chinese furniture?

I just bought two old (1920's) black Chinese chests from an antique shop. They are inlayed with colored shell designs. They are filthy. How do I clean them to their best? How do I maintain them regularly?

Caring for Lacquered and Painted Finishes

Although hard and glossy, antique lacquer and paint finishes can also be quite brittle. Avoid chipping or scratching lacquer by moving furniture with care and keeping surfaces clear of sharp or heavy objects. Do not use water, oil or solvents on the surface. For daily cleaning, use a soft, dry cloth. If the surface is dull or dirty, lightly polish it using a high-quality clear paste wax.

Apply waxes only in accordance with manufacturer’s instructions. If you have an older piece without guidance, some wood specialists suggest that liquid waxes can help restore luster and shine. Again, test first.

Be careful...I would rather have a dirty cabinet that still has it's finish then a ruined piece stripped of the finish.

Good luck.