Chewing gum cannot import without permit.
Bring in amount for personal consumption alright.
Only problem, where is the line between amount considered import
and amount for personal consumption.
I think if you bring in some loose stash in a small plastic bag,
should be ok.
Neat boxes of chewing gum is no no.
But I have brought in some boxes, of 10 packets of chewing gum
each, in my luggage, by walking through customs as nothing to
declare. This is in addition to the "personal consumption" stash I
carry in my backpack.
Done this many times, so chewing gum should not be
counted.