but the bigger worry is that they will end up hopelessly queenless...
if you destroy queen cells and they swarm, you have left them queenless...i think that's where michael was going with that ;) generally, once they have decided that they are going, they are going. destroying the cells does not stop them. better to split the hive and make them think they have swarmed by taking the old queen for your new split.
you can decide whether to let them raise their own queen or requeen the hive. if you split and buy a queen THEN you destroy the queen cells before you insert your new queen.
it's a good question to ask and a good thing to think about. when you have to make that decision, you don't have a huge amount of time so it helps to know before hand what you want to do.