It takes at least 6 weeks for gluten residues to exit from the GI tract, and then an additional 6-8 weeks for the gut to heal from damage caused by gluten.
That is in someone who does not have Candida, Lyme, or other possible issues that would interfere with healing.
Also, many herbal mixes contain an alcohol base or preservative. If you have MCS, then you may not be able to tolerate the alcohol.
Suggest looking into methylation protocols - best links for this:www.dramyyasko.com/resources/autism-pathways-to-recovery/forward/doctorsdata.com/methylation.pdfwww.heartfixer.com/AMRI-Nutrigenomics.htm
Many with MCS have impaired methylation (which decreases one's ability to detoxify metabolic waste, environmental toxins, etc).
I myself have found supplementing with Molybdenum (which supports enzymes that process aldehydes (alcohols), phenolics, histamines, sulfites, purines, xanthines, etc.) and Vitamin B12 (methylcobolamin) to be very helpful for reducing my chemical sensitivities.