I'm gonna have to say the cesium thing is about as applicable as saying Chuck doesn't work because it's physically impossible for something to reach lightspeed (which he did before they errata'd Footsteps of the Divine). TO isn't just doing something that isn't expressly forbidden. It's not TO to declare that your character heals to full HP upon dying because nobody ever says that characters don't do that. TO is taking actual rules that we're given and using them to create something so mind-bogglingly powerful or utterly contradictory to common sense or both that you just have to step back and say, "As amazing as this is, I wouldn't allow it in my game." The only "it's not expressly forbidden" thinking that ever enters into it is when they GIVE you an option through the rules and don't point out specific cases of using that option that shouldn't be allowed. For instance, using a Shaedling to create the Ruby Rod of Asmodeus, or using a spell component pouch to do the same thing, THAT'S TO because they give you the option to generate whatever the hell you want, and don't clarify it.
It's for that reason, for instance, that latter stages of the Hulking Hurler that relied on neutronium, IIRC, don't actually qualify as TO in my opinion, as humorous as they were. The Arseplomancer is the other major example of a grey area where you're simultaneously exploiting the rules you ARE given, and then having to fill in the blank space with assumptions, and I happen to think it just barely qualifies (since the rules seem to be designed for openings in objects, not creatures).