I don't know about a cure, but an old mountain remedy for preventing tetanus after a puncture wound is to soak the foot or affected part in kerosene. While I would not like to expose myself to petroleum products, kerosene apparently draws out the poisons.
The last tetanus shot I had was over twenty years ago when I was bitten by a Copperhead snake. I went to the small town hospital. The nurses called the doctor on call (there were three doctors in the whole county). Sadly, he was too drunk to drive so I received a ton of steroids to prevent swelling and a tetanus shot for some reason. I could not get pain medication because there was no doctor to sign the prescription. I suffered for months from that bites and had a tender spot on my foot for ten years. I think a bucket of kerosene would have worked just as well.