Well effects lab was made more for this. I did this quick test in composite lab. It's not near as good as what Vision or effects lab can make, but it's better then nothing.
First get the video clip you want.
Then Key out the back ground. (I used a color dif. key, it seems to produce the best results.)
Next duplicate the foreground clip by right cliking it, hit copy, then above paste.
Now grade it to where the brightness is all the way up.
Now draw a mask around the blade and change it to invert. Feather the edges. Make sure you dont cover the whole blade, you want to keep the edges.
And now you are done.
Like I said, it's not going to give you the best results, but is better than nothing. Try putting a glow on the top layer, and experiment a little. This took me less the a minute. Good luck. Be sure to post some pictures of your work when you are finnished.
The pictures I used are not mine. I saved them off of the internet. I did do all the stuff in comp lab though.