Suppose it's possible, since I don't know. I know I use it to cook with when I go camping and not only is the flame invisible in sunlight but there are no smells either. Either way, good racing alcohol would be the best choice if I can't get some 10/10 and probably cheaper per volume.

The brass pipe is just a pipe extension of the venturi. It's about 1.5" long and to look at the butterfly valve you have to look down this pipe. I don't have my digi cam, I've loaned it out to someone. The only thing I can think of it being is an extension to draw air from outside a cowl, but why would anyone want to do that? That's completely backwards.