Try using bleach and a toothbrush to clean the grout around your tub. Be sure to wear gloves and safety glasses.
Mix a half cup of baking soda, 1/4 cup hydrogen peroxide, and 1 tsp of dish soap. Apply to grout and let it work for 15-20 minutes. Scrub with an old toothbrush and rinse.
Hi Josephine: Here's a site that tells you how to do that:
Hi Josephine - This is the shower cleaner that we use to help keep grout and tiles clean and minimize the mildew - it works on kitchen grout too. Hope this helps! Hugs, Holly
PS - We have a FREE eBook with recipes for all of my homemade and all-natural cleaners. You can download it here --> https://pinkfortitude.com/thank#GreenClean