That is pretty cool. As I understand it, there's a little bit of a dirty trick to breaking ice. My Soke says that every time he's seen an ice break, the ice has been sitting out for a while, warming up-- the middle starts to thaw and the ice is easier to break. You can tell whether the ice is solid all the way through or not by looking at the block. If it's got a cloudy-white center, then it is not as solid. I don't know if this actually makes the ice easy to break, but it is supposed to make it less difficult. I also cannot testify personally to how true this is (I mean scientifically, I have no reason to doubt my Soke,) but it certainly sounds believable. I thought of another cool break for you to try. This would, necessarily, be a speed break. What you do is, you take a regular taper candle and two sheets of notebook paper. You cut a hole in each sheet of paper and suspend the candle between them. The object is to break the candle and the wick without tearing the paper. I've seen this break done successfully twice, and about a dozen times without success. Good Luck!