You can even staple the bag closed. But now I'm a whirlypop convert. Coconut oil and flavacol popcorn salt. Yum.
Personally I'd just use some kind of metal-free chip clamp instead of actual staples, just to be safe.
I measure a heaping tablespoon of solidified ghee and melt it and add 1 tsp flavacol and toss the popped corn with it to get a similar flavor.
I used to work at a movie theater, this is the way.