A process for treating a surface (2) to clean or otherwise treat the surface (2) comprises a step of contacting the surface (2) with a particulate treating agent such that at least some of the particles (1) roll along at least a portion of the surface (2), wherein an angle of incidence of the particles (1) and the surface is between 0.degree. and 60.degree.. The particles (1) are dimensioned to effect a rolling movement along the surface (2). The treating agent is substantially non-aqueous. The particles (1) comprise a precipitate or agglomerate of an insoluble alkali metal carbonate. The process comprises a blasting operation or a manual application. The use of the process of the invention in dental applications such as teeth whitening and plaque removal, treating bone, and skin exfoliation, is also disclosed. Also disclosed is a treating agent which comprises a plurality of particles (1), the particles (1) being dimensioned to effect a rolling movement along a surface (2), wherein the treating agent is substantially non-aqueous.