A sodium carbonate wash isn't really necessary if you intend to recrystallize, as recrystallization will remove all the stuff that a sodium carb wash would and then some. But for future reference, I have found it is better to have DMT dissolved in a more dilute solution when doing a sodium carbonate wash, and performing the procedure at room temperature, this reduced the risk of losing DMT in the weak basic layer.
Some of the stuff that wouldn't dissolve in the naphtha may also be NMT, as it is only slightly soluble in petroleum ether. If you heated your naphtha and then mixed it with room-temperature sodium carbonate solution, then a lot of the particles suspended in the water may be precipitated DMT. If I were you, I would do a mini naphtha pull on that sodium carbonate solution with all the stuff suspended in it, just to be safe.