I got an old Swing-Away can opener that still works and is clean, but the cutter blade has rusted from repeated washings.
I wonder if the thing is still deemed safe to use, as rust is not something that anyone would want their food to taste like.
LOL - you've got two different issues there, Corey ... food safety and taste. I don't think Ferrous Oxide (rust) is really a bacteria growth medium .... and, hey, most of us could use a little more iron in our diet!
Now - to the other posts - and not directed at Corey ...
I was raised to always wash the can lids before opening ... not only to remove dust but to also remove any possible residue from insecticides that may have been sprayed in the store where the cans were in storage.
I was also taught to always wash my can opener ... and yeah, over time it did get a little rusty ... but that was never a real factor since it was so minimal - more like staining than anything else.
And, yep, got several of those old military can openers - keep one on my keychain. Used them since I was in the Boy Scouts ...
Yep - used my hunting knife to open cans, too ... and the "eagle-claw" can opener on my Scout knife. These were always fastidiously cleaned after each and every use ... I wiped them off on my pants leg.
These days - I'm on my 3rd "clean cut" can opener (the kind that cuts from the side and doesn't touch the food) ... the first two left little fine strands of metal fuzz sitcking out around the lip of the can that I didn't really want to get into my food .. yummy, eating a Brillo pad.
BUT - if I'm opening a can of tuna ... I always reach for the old top-cut can opener so I can press down on the top to drain/squeeze the excess oil out of the tuna.