I hear confessions in the sanctuary.  I often will schedule a time 
that is outside the norm for having someone just "stop by" the 
church, in order to avoid that difficulty.  I'm not sure I like the 
idea of a confessional box.  The reality of dealing with your priest 
in person and getting counseling and penance from a real human who is 
called to that office of reconciliation...I think that is important 
and powerful.

Brian+

PS  use the form in the old priest's manual.