A sachet (1) having walls of flexible material is disclosed. The walls are joined so as to form an impermeable seal, thereby defining a cavity within the sachet (1). A conduit (2) passing through the seal and having inner and outer ends is disposed with the inner end within the cavity and the outer end outside the sachet (1) such that the cavity is in fluid communication, via the conduit, with the outside of the sachet. The cavity contains a volume of liquid (8) in use, and the conduit (2) is adapted to prevent the liquid (8) flowing from the cavity without the application of an additional stimulus, irrespective of the orientation of the sachet (1).