Thanks Preston, would be keen to hear how you get on with it. We are going to split our stronger hives as soon as we have treated them for mites.
You guys are so lucky you don't have Varroa, we all hope you never need to have to deal with them.
I saw the same procedure at a field day last year, the only difference being was they introduced a bought in queen so having frames of eggs was not as critical. Seems fairly foolproof to me, you don't even need to find the old queen as long as you shake all the bees off the frames for the box above the excluder. I'll be giving this a go later this year as I'm planning to split all my strong hives, probably when the black berrys start to flower.