Looks like Tekhelet is, not surprisingly, aware of this property of the Mexican snails.
This page of science clippings includes: "The hypobranchial gland of the muricid Plicopurpura pansa (Gould,1853) is so active that the snails can be stimulated periodically without harming them to expulse the secretion. This property is a great advantage in the study about its biologic and chemical characteristics." from a 2005 article in
Journal of Shellfish Research.