Soda Blasting is very much like Sand Blasting. It works in along with a large air compressor to clean dirty parts and surfaces. But instead of using sand as the cleaning abrasive, a soda blaster shoots out sodium bicarbonate, which is commonly known as baking soda (though what's used in blasters is composed of larger particles than those found in standard household baking soda).
The advantage of using baking soda, as opposed to sand, crushed walnut shells, coal slag, or any other abrasive, is that it's environmentally safe, less aggressive, relatively affordable, and easily rinsed away with water. In fact, the first large-scale industrial use of soda blasting occurred during the 1986 centennial restoration of the Statue of Liberty. It was the only safe and effective way to remove coal tar, paint, and corrosion from the statue's soft copper skin.