After siphoning all the Naptha off, I understand that you have to put the Naptha-filled container (flat glass dish, etc.) in the freezer to cause the dmt to crystallize at the bottom. Then, after leaving it in there long enough so your yield is maxmized, you have to pour all the naptha out and let the rest fan-dry to make sure it's all evaporated.

So what if when the dmt is smoked, a bit of Naptha is left behind in the dmt and that is smoked as well? Won't that cause damage to your lungs and other organs possibly? Someone please enlighten me on this :o

Yep im guessing that smokin naphtha isnt goin to do you any good. I may be wrong but I would assume that if the naphtha wasn't all evapped the spice would just catch fire. Never found it to be an issue though. Just let it sit til you cant smell any solvent. Dont even really need a fan. It doesnt take long at all.

Also, you probably know this but it wasn't clear from your post, dont discard of the naphtha you have leftover after the freeze precip... pour it back into your basified solution. The chances are (IME anyway) that there is still a decent amount of dmt still dissolved in it.

Do an evap test on your solvent to make sure there are no traces of nasties in it. If clean, then it should evaporate clean from your spice.

Depending on the speed of crystalization you can trap solvent inside the crystals. Slower crystallizations trap almost nothing. If you are really concerned you might try chopping up the product with a blade and letting that get plenty of air.