Sorry mate I just don't "see" the nmm effect at all on the blades. I too had the very same problems with trying nmm and also just started on swords and power weapons. Here is a link to a guide I found which has helped me understand nmm much much better and improved my painting.
[url]http://www.youtube.com/watch?v=WJkPRxOH7m8&p=19E961E05E89D972[/url]
http://paintingplasticcrack.blogspot.co.uk
Yeah, this was my first time trying on a weapon. The grey colors I used had more of a blue/white tint then grey/silver unfortunately. Will be making another attempt on a weapon when I get more paints. I've watched that video before and I tried applying some of the technique she explained but the differences in the highlights are not noticable. Need to make more extreme highlights. I had an easier time trying NMM gold opposed to steel/silver.