The present invention relates to a compacted product comprising : - At least a disinfectant capable of releasing active chlorine when contacted by water in an amount ranging from 10 to 99% by weight, with respect to the weight of the product, - At least a strong alkaline agent selected from the group consisting in metasilicate and its salts, soda ash, alkali metal salts of hydroxide and mixtures thereof, in an amount ranging from 5 to 70% by weight, with respect to the weight of the product, wherein said product comprises at least a first layer and a second layer, said strong alkaline agent being present in said first layer in an amount of less than 1 % by weight, with respect to the weight of the product, and said disinfectant being present in said second layer in an amount of less than 1% by weight, with respect to the weight of the product.