Title prepns for cleaning glass windows in smoky or dust laden atmospheres consist of water and/or lower aliphatic alcohols and/or surfactants. The alcohols may be straight or branched chain with 1 to 12C atoms and 1-40H gps. The surface active compounds may be ionic or nonionic aliphatic or aromatic sulphonates or phosphates or polyglycolethers. To the solvent is added 1-40% wt./wt. of a sparingly soluble alkaline earth phosphate (pref. Ca2H2(PO4)2 or chlorapatite) with a particle size of 0.1-5 mu (H) and (pref.) a bulk density of 25 gm/l.
