WARNING! Inside the hair tye fabric is usually a RUBBER band that still emits sulphur. Used only during peformance and not retained in case may not be a problem, but otherwise would be a risk to silverplated instruments. Not my worry, as my instruments are NOT silverplated and I do not store silverplated mouthpieces in my cases. Just the smell of sulphur is obnoxious and would also contribute to a vile smelling case. Sulphur odor is also among those not welcome to anyone with a respiratory illness like me.
It is also a life long nightmare to me with the dosages of synthetic sulfa meds given me during WWII as a child to combat a fever when real sulpha meds were deemed strategic for treatment of wounds to our armed forces. Don't know if such is a recognized med treatment now, but I do know pure sulphur is flammable and an ingredient in matches.