Abstract: Methods of cutting structural shapes by impinging a high pressure jet of anhydrous liquid ammonia or anhydrous ammonia-abrasive mixture at high impact velocity at a target substrate for faster, more efficient cutting/penetration rates i.e., up to 25 percent improvement over high pressure jet cutting methods with water as the cutting fluid, provide greater safety and flexibility, particularly in demilitarizing munitions comprising energetic materials and/or chemical warfare agents. The energy from the cutting jet comprising anhydrous ammonia may also be utilized in a continuous, uninterrupted sequence of processing steps after penetrating a closed casing for dispersing/dissolving and washing out the contents from the penetrated containment for further processing.