I've always wondered about this topic also. I'm going to Cabo (Mexico) soon and was wondering if I should just use the zip ties like you suggested. Just so I understand correctly, 1) if TSA breaks my zip tie they will be doing it for official purposes thus, they'll put whatever new zip tie they have and place a notification inside. but 2) if, however, a thief cuts off my zip tie, there will be no notification inside. And as such, I'd report to the baggage office.

Is that how it works? I'm just a bit nervous about going to Mexico (I have to check b/c I've got big stuff to carry this time) Thank you.