Disclosed herein is a method of initiating oxygen scavenging in a packaging article comprising an oxygen scavenging polymer. The method involves (i) providing the packaging article comprising the oxygen scavenging polymer, wherein the packaging article comprises an interior surface and an exterior surface; (ii) wetting the interior surface of the packaging article with a solution comprising a peroxide, to result in a packaging article with a wetted surface; and (iii) exposing the wetted surface to an initiating factor, to initiate oxygen scavenging by the packaging article. Typically, the initiating factor is ultraviolet light, heat, or both.