Yeah possibly an hour or so
From my experience.you will not get it done.., 15 minutes is plenty ... 60 picks at an hour each? No way it gets done , but see how you go maybe being a Geelong Board PD ..everyone will be into it and it flows well. One can only hope.
Id suggest you come up with rule based on what happens when someone doesn't pick because sure as anything someone will be out or off the board and miss their shot then issues will follow.
Great concept . Its a great chance for all who say SWells doesn't do it well. to show how it would/should be done.