If you have been making your own bath fizzy bombs and they are not coming out just right, you may want to check out these tips from the website Beauty and the Bath:
Essential Oils - Always read labels on essential oils, not all essential oils are safe to have direct contact with skin.
Molds - Try to choose molds without square corners which can be tricky when it is time to un mold.
Humidity - This is not a project to save for a rainy day, the high humidity can effect how your molds turn out.
Conversions - Use this formula to increase the Basic Homemade Bath Bomb Recipe below for your own use or for groups. Use twice as much baking soda as Citric Acid. Then twice as much Citric Acid as cornstarch.
Blending - Always blend and mix ingredients very well, failure to do so will result in bath bombs with a grainy texture.
Containers And Storage - Any contact with water, steam, or moisture can cause your bath bombs to start to fizz. If your bath bombs are going to be kept in a bathroom each bath bomb will need to be individually wrapped in cello or plastic wrap. Or stacked and stored in a container with a tight fitting lid.
For more fun and information check out Beauty and the Bath's pages on Bath Bomb Recipes For Fizz And Fun,