if you know anyone with a grinder or you don't mind spending the time sanding with a sharpening stone (with a little mineral oil on it held more-or-less perpendicular to the blade) a real straight razor dulled so it will no longer cut will always be much prettier and more effective prop. I have also heard of people using PVC glue or epoxy in a really fine bead to cover the sharp part of the blade. using either method be sure to check your blade against paper and then when it cant cut that try drawing it across a inflated balloon to make sure you've rounded off or covered all the sharp parts. I say go with the real thing.