The invention provides an apparatus for treating surfaces of a container. The apparatus comprises an openable reaction chamber housing, an exhaust escapement and an electrode assembly. The electrode assembly comprises a probe assembly coupled with a power source, the probe assembly comprising an elongate wand body, and a helically configured primary electrode and a helically configured counter electrode disposed about an outer circumferential surface of the wand body in an alternating helical configuration. The elongate wand body has a fluid passageway defined therewithin, and one or more outlet openings that are formed on an outer circumferential surface of the wand body and that extend inward through said outer circumferential surface and upto the fluid passageway. One or both of the primary electrode and the counter electrode may be energizable by the power source.