I have tried this method and did not have good luck with it. But, I only hatch shipped eggs, so it may have been this batch was not well taken care of by the post office. I did have to help a couple of chicks out, they didn't seem to be able to get their shells off as well (they were Marans and have a difficult time anyways)...so who knows. It may have been fine and just my set of circumstances...But, I won't use that method again.
On the flip side, I have read numerous posts praising hatching in the egg cartons.
You should try both ways and determine which works best for you.