Look for the best tasting mouthwash by planning a taste test involving several different brands of mouthwash. Purchase five or six different brands, making sure the flavor is the same, such as mint. Pour mouthwash into unlabeled plastic bottles and number them. Enlist several different people for taste testing the mouthwashes chosen and record findings for which one tastes best and which one is the worst. Present findings after polling roughly 15 people.
Gather one cup of sterile water, four test tubes, an eyedropper, a bowl, four petri dishes and three to five different types of mouthwash. Begin by putting mouthwash into test tubes with the eyedropper and leave one test tube empty. The student should then rinse out her own mouth with sterile water, spitting it into the bowl. With eye droppers, add samples of this water to all of the test tubes. After a few minutes, pour the mixture from each test tube into its own petri dish, storing upside for 24 hours. Check for germ growth and record results at the end of the 24 hours.
Create a presentation showing other creative uses for mouthwash besides cleaning a mouth. Compare mouthwash and deodorant for banishing underarm odor. Place a deodorant on one armpit and swab the other with a cotton ball that has been saturated with a alcohol-based, sugarless mouthwash. You can also compare mouthwash with a commercial toilet bowl cleaner. Clean a toilet with a regular cleaner and record results. In another toilet, add a 1/4 cup of alcohol-based mouthwash, letting it sit for 30 minutes before cleaning. Record results.
Create a new mouthwash that is inexpensive and made from natural ingredients. Begin by pouring an eight-ounce glass of water at room temperature. Add one-half teaspoon of salt. Stir until salt is dissolved. Mouthwash can be left as is, or add an essential oil such as peppermint and crushed mint leaves for a hint of fresh mint. Consider running a taste test and entering the homemade version for testing with volunteers.