Yep, we reset the devices after each workshop to give users a clean slate to work from each time. In other workshops, learners can have their own SD card that they bring along each session.
We generally use standard Raspbian and set it up how we like it using PiBakery.
PiBakery is a tool for creating and customising Raspberry Pi SD cards, we wrote up a guide on LibraryMakers.
Then, after each workshop, we can just write the SD cards again.
You could also just reformat the cards and download NOOBs again.