A sealing member is disclosed for use with a wick of a diffuser, or the like. The sealing member seals a vessel containing a liquid in a fluid chamber. The sealing member may be composed of a malleable material that may also be resistant to a liquid fragrance contained in the vessel. The sealing member may include a body, flaps and an opening for receiving a wick therethrough. The sealing member may form a persistent seal when a wick is inserted therethrough, while at the same time allowing venting to the fluid chamber.