I've tried a serrated knife, a steak knife, a carving knife, a stanley blade... I've tried it fast, slow, angled, straight...is it just me?? Is it the type of knife he uses, or is it all in the way Mr Hollywood yields his tool? I can't for the life of me manage to slash the bread without either flattening the dough or tearing it in a most unattractive fashion. Tips please!