An applicator including at least one tube with at least one plug of a liquid or a powder inside the tube. At least a first substance is contained in an inside space of the tube, with the space defined at a first end by the liquid or powder plug. The plug is arranged, in use, to be expelled together with the first substance when it leaves the inside space of the tube. The applicator further includes at least one second substance different from the first substance and dissociated therefrom prior to use. Kit or packaging arrangements are also provided for containing one or more of the applicators.