How about sepsis due to retained products of conception.
Post partum sepsis used to kill many women prior to the days of hospital delivery.
Yeah but clostridium is pretty exotic for causing death, botulism and tetanus not withstanding. Maybe the stuff does something to the gut lining. Sell them in the drug store, Walmart, 7-11 next to the aspirins, so they can pop them like chewable vitamins.