A substitute for Protectan ?

A quote from our local paper ,on the subject of solvent abuse : "Canisters containing a mix of butane and propane, sold in the form of air horns commonly used at sports events, have become the latest cheap thrill for youths....The canisters sell for about NZ $4.00 (US $2.80) each."
Protectan is a mixture of these two gases..
-you may want to remove the horn first..

A JOBO rep told me once that a good substitute would be common propane, available in the small 14oz cylinders at the hardware store.