Exposure to ionizing radiation that will destroy the pathogenic DNA. Maybe a cobalt source.
This method has multiple shortcomings:
- ionizing radiation produces free oxigen ions in the food. Those are highly chemically active and cause deterioation of cells' membranes within human organism.
- it also breaks chemical links within natural biological sunstances of nutritional value (like vitamins, enzymes, etc.) producing others (benzol, formaldehyde) which are carcinogenic and simply toxic.
- some pathogenic species (including the above-mentioned E.coli) can endure being exposed to radiation and then procreate very fast uncompeted from the others.
- radioactive material requires accurate handling what is not the case of household use.
- the sterilisation process requires hours of time (4-8).
So, basic hygiene methods look way more preferable.