Moisten a clean cloth with mineral spirits. Rub grease or oil stains on the wood banister with the mineral spirits to remove them.
Pour 1 gallon of hot water into a bucket. Add 2 caps full of oil-based wood soap to the hot water.
Wet a sponge with the oil-based wood soap solution. Squeeze the sponge to remove excess solution.
Scrub the wood banister to remove the mineral spirits. Rinse the sponge with water. Add more oil-based wood soap solution. Scrub the entire surface of the wood banister to remove dirt, dust and stains.
Tackle stubborn stains on the wood banister by sprinkling baking soda over the damp sponge. Scrub the wood surface to remove the stain.
Rinse the banister with a damp cloth. Dry the surface of the wood with another cloth.