Do you regularly wash your hand can opener? (The one with the gears, not the pointy ones that put triangular holes in your cans.) I wash our can opener because the thought of food transferring to it and cross-contaminating other food makes me gag. The trouble with washing the gears of a hand can opener is that the gears get tight, not turning as smoothly around a can.
The gears were tight on our can opener recently. After thinking logically about the problem, I realized that tight gears need oil. Alas! One can’t use just any household oil on a can opener. No sewing machine oil or WD-40, no sir! Think about that getting into your food. Yuck.
The answer was staring me in the face. Literally. Cooking oil. A little bit applied to the gears with a paper towel or oil dispenser does the trick nicely.
(Hubby says cooking oil also works to loosen up bottle cappers.)