Yeap, that sounds about right... you might want to leave the nutmeg for 24 hours in the naptha though.
If you felt like you wanted to get all kitchen chemist, and extract that you're probably familar with, but with a twist, could also help remove a lot more taste than a plain organic extraction. (Someone could refine this a little, cause I'm not sure about the order extactly).
After you've extracted the nutmeg into naptha, wash the naptha with acidic water (same acidicty as you would use for your DXM extraction (pH 3-4ish)). So add some acidic water, and shake it a lot. Then seperate, and discard the water.. (see if it has any smell to see if you've actaully extracted anything). Then evap the naptha.
My idea is that this could pull some non-polar alkaloids out of the naptha extraction, and those alkaloids are likely to be things which have taste. Hopefully, it should leave the active compounds.
Infact, that would be an interesting test, because there's arguements about where myristicin is the active compound in nutmeg. It, and chemicals like it, would stay in the naptha phase no matter what, but if the active compound is an alkaloid, it would get pulled into the water. So perhaps you should try an acid/base extraction on nutmeg and see if the end product gets you messed up.