In his classic rule for monastic living, Benedict recommends that the community recite the Lord's Prayer together several times a day to help uproot the thorns of contention that spring up in community life. I believe that corporate confession on Sunday mornings can work in much the same way.
Of course, anyone can sleep walk through confession. You may begin to pray with good intentions, and may even be painfully conscious of having done something regrettable, when suddenly you are preoccupied with whether or not you took out the dinner rolls to thaw.