I don’t worry about “sterilizing”. I take along a couple of plastic bags (single use) that were used for cans, or personal products, coffee, etc. .... not previously used for meat/dairy/frozen foods. If the store won’t put my meat, etc. in a new single use bag (to then put in my reusable bag), I have my own single use bags to protect the reusable. It’s not a big deal (for me) & I have had zero issues with illness due to ‘contamination’. People need to just use common sense, which sadly, isn’t so common any more.
I was using the plastic bags in the veggie/fruit dept to put all my stuff in....some people laughed and some “not so much”.
Ask them to point out any item in the store that’s not packaged in plastic. They can’t...other than fruit/veggies but they provide plastic bags for those.
Our stores just give out NEW, unused bags, for all grocery items bought, each time we shop.
Some use paper, some use plastic.
All new.
Then, they typically have a recycling bin located at the store exit, if you’re into that sort of thing, so you can bring their (or, other store’s) bags back.
When I’m asked paper or plastic? I say, it doesn’t matter, it’s all going to landfill anyway.