Coyotero, "Drano" or other drain cleaners are made out of sodium hydroxide which is caustic soda-lye. I have used it in the past to clean traps. This last batch of traps that I got from Tom, I soaked them in a container of water and plenty of Dawn dish detergent. I left them in there for a couple of days. Now they are sitting with a light layer of rust waiting to be dyed. Hope this helped.
Shawn