I would throw caution to table salt , it has aluminum in it which is hard for the body to rid even with a heavy metal chelator. Also since Morgellons has an attraction to metal I don't advice any products that have aluminum. Baking soda can also have aluminum (look for aluminum free). This information was given to me by a practitioner I'm working with, but I also have a medical book that confirms it called "Prescription for Nutritional Healing" by James F. Balch, M.D.
Also, I am someone who had serious reaction to doxycycline and not in a good way. I went from small red bumps in a small patch on my chin to 90% covered in lesions on my whole body over a course of a three months prescription where the doctor kept using larger doses and telling me it would pass. It did not, I continued to worsen until I ended up in a huge mess. I have spent over a year and a half trying to correct what had happened. I would never recommend this Antibiotic to anyone with Morgellons, it was my worst nightmare. I do know everyone responds different, but I do caution this along with anti-depressants that are so commonly issued to Morgellons sufferers. For me, these are lethal and I won't touch them with a ten foot pole. I am someone who did have parasites (doctors didn't acknowledge this) so maybe due to not ridding the parasites this Antibiotic had caused the flare-up.
Itching to me is not a good sign, after six long years I've found itching to be a sign that it is multiplying or stimulated below the skin. Itching, pinching, and any skin irritation will subside if you are using something that kills it or slows it down. You definitely want die off where it dries up and comes out of the skin. When you aren't getting anything out it's time to worry again cause it means it has adapted to what you are doing and the whole process starts up again.
That's just my experience, someone else may be different.