You can use sublimating dry ice to produce carbon dioxide gas to fill bubbles. A small piece of dry ice will produce cloudy bubbles for a long time. Here's what you do.
Dry Ice Bubble Materials
Make Dry Ice Bubbles
This is one of the easiest projects there is! Pour a little bubble solution into a bowl. If you don't have bubble solution, swish a small amount of liquid dishwashing detergent into water. Use tongs or gloves to pick up a piece of dry ice. Add it to the bubble solution. That's it!