Branchpipe with built-in soap cartridge in a refill case. The wetting agents contained in the case dissolve when water passes through and break its surface tension. This facilitates the penetration of the water into porous to low-permeability substances, such as textiles, foam materials, styropor, wood, hay, natural or synthetic fibres. Apart from that the foam film created impedes the ingress of oxygen. The effectiveness of the available amount of water is therefore much greater.