I use Clorox toilet cleaner, let it sit a few minutes lightly brush in the grount,,,,rinse w hot water ...works great in grouted.floors
Was the grout ever sealed? If not, once you have it clean you might think about sealing it to make day to day cleaning easier. Vinegar and baking soda is what I use.
Hi Ron - There are several ways to get rid of mold in your bathroom, but most importantly, you need to address the root cause to keep it from returning. This is a great article that covers methods of how to remove mold, if bleach is safe to use, and how to prevent it from coming back. Hope this helps! Hugs, Holly
If it’s a small space you can use a bleach pen