The problem that people have always had getting RR sessions organised in the past is the problem of getting that many members to commit to turning up on the day (and paying in advance, so that the organiser isn't out of pocket if anyone doesn't turn up). Considering how difficult it can be to get 15 people to turn up to Regional events, like the recent East Anglian meet, or the Yorkshire meets etc., it could be difficult to get 15 members to sign-up for a RR session. Don't let me put you off - if you can get 15 members committed good luck to you.
You might need to set up a session provisionally and then advertise it on .com, .net, migweb, VBOC etc. & see if you can get enough people interested. 15 members at 30mins each would take over 8 hrs (allowing for changeover times) - a full day. If sessions are a bit shorter, it might take less time, but not everyone will want to hang around for the whole day.