If I used plastic jars/lids, I'd probably wash them after I purchased them, but for glass Ball jars with metal lids, I really don't see the need. I do run used jars through the dishwasher (which is basically the home equivalent of an autoclave for sterilizing) and just let them air dry, since towel drying can actually introduce debris. Lids I just wash in hot soapy water and towel dry.