It might work, but thinking about myself when was developing for a living, I would probably prefer to work on my own pet projects (freedom to do things in my own timescale, my way, and to drop them if I want), unless I'm being paid properly for my time.
So I'm not sure money for drinks will create the incentive you need for what you have in mind. I'm not saying don't try, just giving my explanation for what we've seen so far.
From my experience of trying to get people together to work on SAFEpress, and the other open source project I know people from (remoteStorage), I think you need at least one person who can drive it, the main designer and developer who is capable of doing the difficult bits and will just get on with it, while also sharing their vision, going out and talking about it. With that, you can attract a team, if you're lucky to be doing something that inspires others to want to see it happen.
Otherwise, I think you need to be able to pay rewards that are worthwhile. Maidsafe has attracted both for building the network, but with the apps, I think people like to work on pet projects that interest them, or work in a more professional basis.