At the lab, we go through ~1 container a day and they are just normally tossed out. I save them and then use them to sprout seeds, gemmae, and leaf cuttings. As you can see, they have a hinged cover to keep in moisture. It also has an inner container with ~100 - 1/4" holes for drainage. The container it fits into acts as an "open tray".
I'd like to offer this "grow chamber" as part of a trade or for new people who have nothing to trade. My grow list is a click away, if people want to go that route.