If you home can your food, here is a tiny tip that will save you some time and trouble. When you open a jar to use the food, save the "cap" and wash it when you wash the jar. Then, when both are dry, turn the cap upside-down and gently screw on a ring. Place in your storage area.
When it is time to can, your jar will be perfectly clean, no dust inside, no dead spiders... Voila!