I stuff all empty containers full of stuff.
If I don't do that then I am just packing empty air around.
I like things like Nalgene lab bottles for anything that can be squeezed and leak.
Toothpaste is nasty to clean out of your pack once the tube has ruptured.
I just try to avoid putting toxics into food containers.
Neither matches nor hand sanitizer are toxic, but they can be stuffed inside of a baggy first if you are worried about them.