Follow these steps:
Make a paste of two tablespoons of baking soda and a little water.
Apply it directly to dark or moldy stains.
Use a small brush or cotton swab to thoroughly clean the corners.
Leave on for about ten minutes.
Rinse with clean water and dry thoroughly.
Repeating this process many times causes the fungus to regrow.
Use toothpaste for a quick freshen up
Toothpaste is a surprisingly handy tool for cleaning synthetic surfaces. Its mildly abrasive properties help remove stains and restore natural color.
