Yes, it is usually possible.
The most difficult is to ask it for the first time.
I didn’t dear from the first time neither. But now that I’m not afraid to ask, I usually get comments from the clients behind me “oh, that’s a good idea!”.
Do you know that shops have hundreds of euro cost for packaging per month? So, most of them will be happy if some clients help them save money… and they sometimes compensate with giving something extra 😉
the food safety organism doesn’t like it… but let’s make them adapt to more environment friendly laws! the Food safety agency allows using you own packaging (at your own risk) for ecological reasons, if those are clean, and adapted to contain food (update Nov 2019; link here).
I know, you’ll tell me that you don’t have time to stop at the butcher, zero waste, bio and fish shop. Going once a week to the supermarket for few hours is mentally (and for the planning) easier. But those small shops, they might be next to school or work…. If so, you could spring in just before school, or quickly after school, or during lunch break. It is just another way of filling in those “lost time”; otherwise you would probably quickly go on Facebook or internet because you have to wait… But if this doesn’t work for you, find another challenge.
Or you can also ask at the supermarket (if they have a counter for cheese and meet), some of them accept to use containers from clients.
You can maybe give it a try?