This is a myth. You can use any torch you like. Butan toches can be refiled so this is why the average head shop torch is butane. A propan torch is large and looks like you are maybe cooking meth with it on your table. But you can use any torch you like to heat up your banger. The best thing is to not overheat the banger or it will be chazzed. Learn more about a chazzed banger