Secure?

Recent world events have resulted in a change in airport security. It seems there are 3 things that can be carried on an airplane, each of which is benign and uninteresting in isolation. Two of them can look like liquid, gel, lotion, something like that. The other is a filament such as one would find in a christmas light or a camera flash bulb. If you were running the TSA, which would you choose to ban from all carry-on bags? Would you choose to disallow all items of a particular consistency, or would you focus on the less common but essential ingredient that has the added bonus of being metal and thus detactable using the methods currently in place?