I am also going to either pre-bag each item in Ziploc sandwich bag OR do that when the kids are at the door, if they'd like to have separately bagged.
We don't get many trick-or-treaters, so I can bag as I go.
But if we had tons of kids coming, I'd already pre-bag.
WHY BAG? you ask . . .
because if the safe nonfood item is going into a bag of unsafe candy, I want at least that barrier for it.
Having seen how the Reese (especially) can come open/unwrapped, I'd just feel better.