While of course I will make reference to the term — it’s news, baby! — I don’t think the phrase is as great as everybody else seems to. You don’t eat Satan, and you don’t coat sandwiches with sugar. I like colorful phrases as much as the next guy, particularly if the next guy likes them a lot, but I think they should have an internal consistency to really work. I’ve been trying to come up with an alternative, but so far they have other problems, too much explanation required, not enough alliteration, etc. Still, a few meager attempts:
Lucifer’s lunch bucket, once you open it, all Hell breaks loose.
Mephistopheles’ M&Ms: candy coating on the outside damnation on the inside.
Pernicious Peanut Butter Cups, tasty chocolate on the without, agony within.
A Satanic Transvestite: looks good until you see what’s under the clothes.
Maybe the commenters can come up with something better.