As far as I am aware, you cannot store Thieves tools, or containers (unless herbalist bags/alchemist flasks - no magic bags or boxes). From what I have gathered it was because of a bug that allowed them to be used while stored, effectively being an exploitable problem. The bankers take brains, hearts, and other smelly things, crammed into little jars, so I don't think it's a content issue. I myself have torturers tools stored <_<