Removing Black Grout Stains?

[Stacia]

I have just had the same issue with black grout changing the colour of my white tiles. We’ve only done a test area which will be hidden by a vanity unit but what is the best way to move forward? Thank you all.

 

[Jdouth]

Thanks for the astonish recommendation literally saved my life a god scrub and all my worries went away ...thank you