A flowable medium distribution device (10) comprises a chamber (12), a distribution member (30), a dispensing membrane (24,40,68,72) and bristles (36). The chamber (12) is configured to contain the flowable medium (62). The distribution member (30) includes an aspect (32,34) from which the flowable medium is to be dispensed. The dispensing membrane (24,40,68,72) is disposed on the aspect of the distribution member for dispensing the flowable medium on at least one surface to be treated. The dispensing membrane comprises a plurality of uni-directional dispensing outlets (26,46,70,74), operable between (a) normally-closed and (b) open positions. The bristles (36) extend from the dispensing membrane and are for contacting with the surface to be treated. The dispensing membrane (i) dispenses the flowable medium through the plurality of unidirectional dispensing outlets only in response to application of a differential pressure across the dispensing membrane equal to or exceeding a threshold, wherein the uni-directional dispensing outlets open for delivery of the flowable medium, and (ii) responsive to the differential pressure across the dispensing membrane being less than the threshold, the uni-directional dispensing outlets return to a normally-closed position which terminates delivery of the flowable medium (62).
