A device for oral application of a substance, comprising an inner tube surrounding a first volume an outer tube surrounding a second volume, the second volume comprising a cavity section adjoining an inlet opening of the outer tube being adapted for containing the substance, a separation area arranged in the second volume, the separation area adjoining the cavity section and the first volume, and a selective connecting passage between the cavity section and a pressure compensation space to selectively enable a flow of the substance from the cavity section though the first volume. A kit-of-parts, comprises the inventive device a predefined amount of a substance being contained in a receptacle or the cavity section, and instructions for the use of the substance. Methods for filling the inventive device as well as to a method for oral application using the inventive device are provided.
