I do take a little bit of merit in the snake bite venom extraction. If your not in proximity to medical treatment, there needs to be an attempt to get as much poison out of the area as possible.

Most snakes won't pump all their venom, but in the rare event they do, it is critical to remove as much as possible. The quantity and spread of the venom will determine the amount of tissue death in the area of the bite.

So even if the odds are against it, my own position on the matter is to get as much out by whatever method can be safely applied immediately. Once tissue death starts there is nothing you can do but watch it happen.