The invention provides a method for the treatment of polymeric particles recovered after use in cleaning processes for soiled substrates, the method comprising treating the particles with a particle cleaning agent. Preferably, said agent comprises at least one surfactant. Preferably said agent comprises an aqueous medium. Typically, the polymeric particles comprise particles of nylon or polyester. The invention also provides a method for cleaning a soiled substrate, the method comprising the steps of: (a) treating polymeric particles with a particle cleaning agent; and (b) treating a moistened substrate with a formulation comprising a multiplicity of said treated polymeric particles. Most preferably, the substrate comprises a textile fibre or fabric. The results obtained are very much in line with those observed when carrying out conventional aqueous cleaning processes and the method provides the significant advantages that the useable lifetime of the polymeric particles is maximised and the economic and envi
