Im not at all familiar with cocoa fiber as I never seen it or used it. Meals worms are amazing with survival and Ive found them as beetles in my terrariums living in the walls and they did a lot of damage. Im not sure about keeping them in the frog home, My concern is the mess with mould and bacteria. Meal worms don't do well in the slightest bit of moisture and it may course problems. This is Just my views so hopefully someone else may know more .