the case that a cloth is treated with a processing solution containing only sodium dichloroisocyanurate in an effective chlorine concentration of about 0 4 by weight can be attained that is the cationic surfactant functions as a filler for the bleaching agent a suitable amount of the cationic surfactant is from 0 005 to 0 5 by weight preferably from 0 01 to 0 05 by weight in the aqueous solution if the amount exceeds 0 5 by weight a rinsing operation in the subsequent step becomes likely insufficient the bleaching effect of a cloth increases in substantial proportion to the amounts of the dichloroisocyanuric acid salt and cationic surfactants added accordingly though it is possible to control these amounts if the effective chlorine concentration is less than 0 05 by weight desired results cannot be obtained even though the amount of the cationic surfactant added is increased further if the effective chlorine concentration exceeds 0 4 by weight the bleaching by combined use with the cationic surfactant markedly proceeds whereby yellowing of the cloth so called as 34 chlorine yellowing 34 is likely generated moreover though the cationic surfactant may be used in combination with the above described basic compound and nonionic surfactant it is not preferred to.