What is the proper way to maintain a can opener?
I have a lot of canned food and have gone through my share of can openers. I'm generally OK with a rusty can opener, but I don't like the rust flakes getting into my food. I can't bear that metallic taste.

While I don't mind buying a new can opener (they sell them at the dollar general for two dollars), but I find it a bit wasteful.

This may sound a bit un-orthodox, but I use rubbing alcohol (90% or higher). I have a jar filled with it next to the sink, so I will rinse the can opener off, dip it in the jar of alcohol, and put it back in the drawer. It dries fine in there.

This also works for other rust-prone utensils like whisks.