Originally Posted by
justcorbly
The choice of 3 oz versus 100 ml is likely down to commercial availability on either continent, plus not allowing anyone a container large enough to make something nasty.
AFAIK the TSA allow containers - large thermos mugs etc.. - provided they are empty of liquids.
I suppose some
containers might attract more attention than others. But AFAIK, there's no rule against any empty container.