Wally said the process is guided by the swarm organizer bees, and
they are field bees.
The strategy is to keep the swarm organizer bees separated from any
Queen Cells they
want to control for a couple of weeks. That is, until the swarm
organizer bees ages out.
Once the swarm organizer bees age out the likelihood of swarming
disappears.
Wally's recipe says swap the mother colony back, and take out any
swarm cells the queenless half of the split produced.
His recipe assumes the queenless half will make poor quality queens,
but he says, if the look great, swap them into the colony you swap
the original queen out of.
Unless you have a good reason to do something different, my gut says
follow the recipe.
That being said, we're free to try things out, and make mistakes.
What we try may or may not have an affect on the outcome. (namely
the goal is to prevent swarming for the season)
If the strategy fails, the worst that can happen is we get a swarm,
and realize we did something wrong. Lesson learned.
that's my 2¢