Presumably all residents signed a lease agreement at the time of purchase where they agreed to pay an annual fee to the managing agent/company for performance of certain tasks such as maintenance of communal areas, refuse etc.? If so, this would be the first point of reference when deciding what action can be taken.
On what basis (if any) are these owners not paying?
I'm not sure about the 'no win no fee' basis, I would think that would only apply to personal injury cases and the like, not enforcement issues such as the one you have outlined.
Perhaps you could talk to someone in an agency like Wyse who manage quite a few developments around Dublin and get their advice on the issue (maybe they won't be willing to talk, but it's worth a shot as I'm sure they deal with this sort of thing all the time-how successful they are in getting a resolution is another matter.........)