Have you tried:

50% Bleach and 50% Water solution.

Baking Soda: Make a paste with baking soda by adding water. Apply it to the stained areas, and let it sit for a couple of hours, then clean with a moist cloth or sponge. Wash as normal and let dry.

Dawn Power Dissolver is designed to remove stains. Just soak in warm water and Dawn for at least 30 minutes to one hour. When the discoloration is gone, rinse and dry.

Lemon: Just rub with lemon juice and leave it in the sun for 1 or 2 days. A combination of the lemon and the sun’s UV light will remove discoloration, and it will also kill bacteria.


Dean
Photographs:
https://www.instagram.com/deanwilsoncanby/
https://fstoppers.com/profile/deanwilsoncanby
https://www.facebook.com/Dean-Wilson-Photography-112841337020414

Please don't confuse your "Internet Search" with my licenses, certifications and over 30 years experience.

"Thank you for calling Technical Support. If you feel you have reached this number in error, please hang up and press redial."