A Bahtinov or Carey mask is likely to work better. See the thread
http://www.iceinspace.com.au/forum/s...ad.php?t=47090 for one member who makes them. I bought two from him.
A NexImage is only likely to pick up fairly bright stars. It is only intended for solar system work.
What scope are you using? On my C8 it does work down to about mag 5 or 6 but that's about it. I would not use it for deep space photography.