Carboxylic acid diesters are employed for treating, in particular for cleaning textile and other materials, and more particularly for removing paint stains from textile fibers to improve the cleaning thereof; the subject formulations contain at least one dicarboxylic acid diester having the formula (I), R1—OOC-A-COO—R2, in which R1 and R2, which may be the same or different, are each a linear or branched, cyclic or non-cyclic C1-C20 alkyl, aryl, alkyaryl, or arylalkyl radical; and the group A is a branched divalent alkylene radical; and including at least one nonionic polyalkoxylated terpene surfactant.