To get rid of the nasty black gunk in your drain: 1. Boil a pot of water. 2. Meanwhile pour baking soda down the drain. 3. Once the water has reached a rolling boil pour it down the drain. 4. Let the water and baking soda work at decomposing and sterilizing the grime for 10 minutes. 5. After 10 minutes, pour 1 cup of bleach down the drain to completely kill any remaining mildew or bacteria. This process every few months. It will also keep the nasty mildew smell at bay. THIS IS AWESOME.
Keep this in mind if you start seeing lots of spiders around your place. Natural spider killer or preventer...take one cup of vingar, one cup of pepper powder, a teaspoon of oil and liquid soap. put it into a spray bottle and spay along the outside of your door(outside door) and along windows refresh after it rains.