Do not use Mouth to try and suction out venom! Whatever miniscule amount of venom you could draw using your mouth will not be worth the risk of exposure. Should your mouth come in contact with any venom, the membranes in and around the mouth are very permeable to venom and you will become a victim as well. Spitting once in a while will not eliminate all the venom, and what remains or gets absorbed in the meantime will put you in a real crisis.