naphtha contains benzene which besides being a carcinogen is also known to cause nerve damage. i actually suspect it is a part of the cause of my own PN. lye also is known to cause nerve damage. im not a chemist and dont know how much of each ends up in the crystals but these may be your culprits right here rather than the dmt itself. smoking them will certainly get them into your bloodstream more quickly and to a greater extent than skin exposure. keep taking supplements that promote or provide the environment needed for nerve repair and growth. a healthy life style in eating and exercizing also may help. I havent found any miracle cures for exposure to toxins, hopefully since the exposure is over and there will be no further exposures you will be able to heal over time.