First extraction using Bartoline White Spirit yielded very little dmt. I followed the tek to the letter and yet the freeze precipitation was slow... Crystals melted super fast and I could retrieve only 300-400mg from 100g of MHRB.

Maybe my freezer didn't work correctly, I checked the temperature with a laser thermometer : -30c.

Was it the bark?... Another extraction using the BLAB tek and got 2 grams out of the first three pulls using the same MHRB.

Then it hit me... it must be the white spirit. I went down to the grocery store and got a bunch of Zippo Premium Lighter Fuel...

Bingo... Next extraction was perfect!

White spirit (heavy naphtha) clings onto DMT more strongly than light naphtha.

I would not rule it out as a non-polar solvent, I have had good results with it in the past. I think your post title is slightly alarmist.

I have worked with white spirit, going completely the opposite route than is normally advised. Due to its low cost I tried adding excessive amounts in my pulls, after freezing it dropped out as easily as light naptha. Considering the talk about it not being a good solvent to work with, I was nicely surprised.

If you have issues dropping spice out of your solvent, another route to go is salting out the DMT with vinegar, rebasing and pulling using a less greedy solvent.