yes, I use old canning lids to top off my storage jars, as well if I wash out a jar, I put the old lid on so the jar stays clean and no bugs....
I do the same, but those jars still go through the dishwasher on a sanitize cycle before filling. Had a bad experience one year, and ended up tossing 80-ish pounds of tomatoes. Broke my heart...
Blue Diamond nuts plastic lids are the perfect size to cover many cans. Cat food cans, spaghetti, chili, etc. Saves on plastic wrap and foil. Or just put a saucer on top of leftovers.