The principle of dry ice blasting is similar to sand blasting using no sand but frozen CO2 pellets as blasting material. Dry ice (CO2) pellets are accelerated to over 150 m/s speed and cleaning the surface. The pellets are accelerated by compressed air and applied using a hose and a blasting gun, just as with other blasting methods. The pellets sublimate as CO2 gas into the atmosphere immediately after hitting the surface. Absolutely no cleaning material remains. The removed dirt falls to the ground and has to be swept away.

Dry Ice cleaning removes:
Paint/coating, oil, grease, tar, bitumen, dirt, ink, resin, adhesive, wax, binding/release agents, silicone/rubber residue, chewing gum, graffiti, and much more

This video gives a quick introduction to Dry Ice Cleaning