It's not just large amounts of liquids: it was my understanding that this is both a restriction on large amounts of liquid, but particularly on large containers needed for an explosive of sufficient destructive power.

You could always easily work around the liquid amount restriction (multiple containers over multiple people), but if you still need a large container, it becomes harder.

I don't know if this is true or if a resealable plastic bag also works, for instance (that would be funny, wouldn't it?).