I had no idea that dry ice could be used to clean just about anything. Essentially frozen carbon dioxide, “dry ice” can be blasted onto surfaces to help remove dirt, grime, grit, and other debris.
The simple explanation of how this works is that dry ice, at a temperature of about -109 degrees Fahrenheit, is so cold that it causes dirt to shrink and lose its adhesion to a surface. When the dry ice (solid) is blasted onto a surface at high speeds, it immediately turns into gas and dissipates, causing the loose particles that it comes in contact with to fall off.
Modern Marvels on The History Channel explaining the process of dry ice blasting.
A company by the name of Coldsweep was contracted by the Utah State Government to clean the roof of the Utah State Capitol in 2007.
Here is Coldsweep, a dry ice blasting company that was responsible for cleaning the roof of the Utah State Capitol building.
Dry ice blasting has lots of potential uses including fire damage restoration to structures and even books! The dry ice blasting technique is better than traditional sand-blasting because it leaves behind no residue or buildup, nor does dry ice blasting create any harmful environmental effects. Dry ice blasting is also delicate enough to use on important historical documents and has already been used to clean old books.
Clean snow does a decent job at cleaning dirty shoes.