setup separate class to work on aiki. over time, folks will integrate aiki into their aikido by themselves or not. trying to do aiki in the traditional aikido class is a losing proposition.
lets face it. aiki works are not sexy. folks like to do big throws, big beautiful ukemi, umpteen ways to do shihonage, etc and etc. aiki works are just work, work, work; tedious work, boring work, and time consuming work that take years to realize the potential if any. it's not one of those fast food aikido thing.