I have had good luck with it on insects but even with our discussion a while back had indicated it wasn't useful on snakes. I still would probably try it, if I had nothing to lose and help wasn't coming or self rescue wasn't possible. I had remembered the story nighthiker had told with the marine who got bit on the hand/arm and he tried it and it still had swollen up, etc..
I wish something would work but it seems no matter if it's electricity, suction, voodoo doll or what have you, if you don't have antivenin you are going to be in big trouble.

http://forums.equipped.org/ubbthreads.php?ubb=showflat&Number=99868&page=3