Tetanus shots have nothing to do with preventing blood poisoning or rust getting into the blood stream.
I have never had a tetanus shot, neither have any of my family. Its never been a problem. I personally think the chances of getting lock jaw from most cuts and gashes is very slim.
Alternatives are cleaning the wound with soap and water.
Spraying wound with Colloidal Silver and taking it orally.
Taking vitamin C megadoses.
and if you search cure sone I imagine there are plenty more alternative too.