Anhydrous ammonia and propane cylinders

(Caution! This could happen in Canada

The brass valve in a propane cylinder will be damaged if it comes in contact with anhydrous ammonia. This deterioration will lead to cracking of the valve body or its components and can ultimately result in a violent, unexpected expulsion of the valve from the cylinder, causing personal injury or death.

Background and Recommended Action

It has come to the attention of the National Propane Gas Association that propane cylinders are being used in the manufacturing of Methamphetamines. This drug is commonly referred to as 'crank'. Manufacturers of this illegal substance are using propane cylinders for the storage and the use of anhydrous ammonia. These cylinders have been found in many states at cylinder exchange and refilling locations as well as in hotel rooms and mobile laboratories, where the manufacturing of this illegal substance takes place.)
http://www.npga.org/i4a/pages/index.cfm?pageid=529

let them blowthemselves up

is there any other way to speed this process up?