Yeah, this is a strange mix of information being conveyed. Tetanus is indeed caused by an anaerobe, and it’s caused by a puncturing wound. The depth of the wound is what causes the oxygen-free environment. The correlation with iron, from my understanding, is solely because a nail can easily cause such a puncture. A nail stepped on in the general environment can easily innoculate the wound with with the relatively common Clostridium tetani bacteria, which causes tetanus. I don’t think rust is a factor, though I’ve been wrong before.
Can licking an iron bar get you the daily recommended amount of iron?
How many licks would it take? Can the iron in bars even be processed by the body? Can you do this for other minerals?