As a packet it would be easier, i could maybe take the label off possibly.
As a packet, I imagine it might look something like mine, but generally it looks like regular salt (but the crystals are a lot larger - like the citric acid that you get for cooking/descaling kettles - so you could claim it's that). It won't smell of anything, because that would mean air could get into it, which would spoil it.
LW SN (out of stock atm) is in a tub with printed label. No good.
Personally? I think a tub would be safest... even if it's a printed label, just apply a
little heat using a hair-dryer or something (to warm up the glue), and the label should peel right off. You could then use a sharpie to write something else on it (but nothing food-related because you wouldn't want someone to open it).