what are your metal prices , recycled metal long short , alum. copper????
it depends on what you need to do with the sterile metal. while shoving it in flame does sterilize it, the spores remain. there is a reason why surgical equipment(mostly metal) is put in an autoclave i.e. put in boiling water under pressure (10-15 psi) for 15 mins. at home u can autoclave stuff by putting it in a pressure cooker for 20 mins.
Just wash them in scorching soapy water and rinse them good, Germs have a rough time surviving on ceramic/porcelain/glass, that is why there are extra germs on kitchen sponges than there are on bogs. Excelsior!
put it in water and bring to the boil, boil gently for 5 minutes and the metal will be completely sterile. (anything boiled for 5min will be sterile...if it can take the heat)
Use fire to heat it up. Thats the only quick way I know about.
The quickest way is to hold your metal piece with an oven mitt and put the active end in a bunsen burner flame for a few seconds. It is much faster than water.