My plan for favors is a chocolate square and a just-add-water cocoa packet inside a glassine bag, folded over and sealed with a "thank you" sticker. We'll have coffee and hot water for tea at the reception, so I figure it will be easy to drink the cocoa there, but small and tidy enough to take back to hotel rooms if they'd rather. Thoughts?
I'd also like to note that I plan to purchase cocoa packets that are GF to 20ppm, which is safe enough for my only GF guest, and to my knowledge, milk chocolate is considered vegetarian but not vegan (and I only have vegetarian guests, no vegans).
Re: Chocolate+Cocoa
I would probably stick to one or the other. Food is a great favor, so I think either one you do will be a hit!