Yes, as Phil said, for a week. Don't keep the cocks locked in, let them out one at a time then two at a time gradually building up until they all know where their own box is. When you reintroduce the hens lock them all in then put the ones that were already paired together, pair the others keeping the boxes locked and watching that they are paired. I put a 2.5litre paint tin in each box so the hen can go up on it away from the cock. Watch that they do pair - he should spin and coo and she should walk proud and sort of nod her head. When you've got them all sorted, you can let them out and the cocks should call the hens up to their box. After a couple of days put the nest bowls in to encourage them to lay.
This is what I do and it works for me. Others may have other ideas. :-/