The process uses dry ice particles (solid CO₂) of varying sizes depending on the technology used. These particles, accelerated at high speed towards the surface, strike the layer of dirt, instantly cool it and shatter on contact, generating a dual mechanical and thermal effect. The impact of the micro-particles, combined with localised thermal shock, causes the immediate detachment of contaminants without damaging the underlying materials. The result is a deep, rapid and completely dry clean that produces no secondary waste and requires no solvents or abrasives.