Kenny, I don't 'wash' my can openers, unless they have an awful lot of food on them. If necessary, I rinse immediately then dry them with a clean cloth.
Maybe I do it differently than others but not much food gets on them in the first place, if any at all - so why wash?
But seeing as you do, why don't you also wipe them down with some oil? Not a lot. I have a pair of kitchen scissors that will rust if not dried properly. I spray with oil and wipe down really well before putting away.
If you feel you can't get into tight spots, use an old toothbrush. Use it to 'wash' and also dry (wrap a clean thin towel around it) and last but not least, use it to oil your wheels.
Meddle not in the affairs of dragons for you are crunchy and taste good with ketchup.