I'm looking for something that is able to totally strip the jpeg preview file(s) from a NEF file. Not something that will simply copy the jpeg's but actually remove them. Catch: I'm using OS X. Anyone have an idea ?
Even if you do it you will end up with a non standard NEF format. The whole point of NEF format is that it comes out of the camera and never ever gets changed - with the exception of Nikon software such as Capture NX2.
If you have a non standard "negative" you can never be totally sure in the long term that it will be readable. You should abandon this idea, there is a good reason why no one does it.