This is a bit late in coming, and I'm not sure if it's any easier, but I get the seeds out by whacking the backs of the cut pomegranate halves with a wooden spoon and then put them through a food mill. So easy, a kid could do it (http://gardencorrespondent.com/2010/11/01/juice/). I have never used said juice to make grenadine before, though, and I have resolved to try it when pomegranate season rolls around again!