Sponges are great places for bacteria to breed. While most of the 362 types of bacteria that can be found on a sponge won't hurt you, according to the UK's National Health Service, it's always a good thing to sanitize sponges regularly.
After each use, put your can opener in the top rack of the dishwasher and put it on sanitize mode. If it has stuck-on grime, dip a wet toothbrush in baking soda and give the gears and blade a good scrub before putting it in the dishwasher.
Have you ever thought about how often you clean your oven mitts? I know some people that never wash theirs.
Consider this, though. Your oven mitts get food dripped on them, and then they touch your cooking pans, possibly spreading germs and mold spores from decaying food particles. Or even worse, they may spread salmonella and E. coli if they've touched raw eggs or meat.
Toss your oven mitts in the washer once a week or sooner if they've touched raw foods. Make sure you put them in the dryer too, but only if the material they are made of can survive it. The heat will kill any remaining bacteria.
To get the blade area extra clean, twist off the base of the container. Take apart the blade and rubber gasket and scrub them down with warm water. Let them completely air dry before you put the blender back together.