In 2018 we introduced STERLING, a framework designed to encourage citizenship to develop recycling habits. This framework is composed by a low-cost, low-energy sensor installed in recycling containers to measure fill level and other physical parameters, together with a mobile app and an associated web-based server. The sensor is activated magnetically each time the container lid is opened by a user. Instead of directly sending this information to a cloud-based server, our sensor broadcasts a Bluetooth Low Energy (BLE) packet to the surrounding area. An app running in the mobile phone of the user performs two actions: To capture this information, re-sending it to the cloud-based server, and to assign credits to this particular user for having used the recycling container. In this way, users are rewarded for using the container, and the infrastructure benefits from cost-free communications from the container to the server. During the first semester of 2019, we have launched a pilot demonstration of the STERLING solution at different schools of the University of Valladolid. This test included the deployment of ten STERLING recycling containers, making a public presentation to encourage users to improve their recycling habits, and running a rewarding mechanisms consisting on Amazon gift cards. In this paper we describe the experience in detail, showing the advantages and weaknesses of our solution, discussing some interesting lessons learned from this experience, and pointing to further research directions.