Dry ice would both bubble AND fog. It bubbles rather violently which produces a nice sound too.I'd say an old aquarium air pump from a garage sale for the bubbling, and either a lot of misters, or, and I really hate myself for saying this considering the danger factor, but dry ice for the mist. Dry ice may only be used if 100% guaranteed that no one, and I mean no one, can come in contact with it.