We have communal penance services all over the Milwaukee Diocese, but they always end with individual confessions.
Our pastor brings in 6-8 priests (sometimes the Archbishop comes) and everybody present offers an individual and private confession to any priest there. And it's not one or two sins, either.
It's quite moving, and I love it. My husband and I are going this coming Wednesday to a neighboring parish because we missed ours last week.
**but they always end with individual confessions**
That's the way it's supposed to be!