Look @ it this way...when it comes to germs/ bacteria, etc...
When you handle & cook raw chicken or a steak, did you ever get sick?
Not really, bc you make sure you're handling the raw meats safely, clean the prep area. Same w/ their raw food.
Do you disinfect the sponge? Not really right? You just use it on all the other dishes...nobody got sick right?
I personally have a separate sponge just for their glass bowls. But I have used their sponge by mistake to clean human dishes! gasp LOL
but I knew it was cleaner than our sponge bc I use hot water on theirs' & not really on ours'.