First, wipe down the grout with hot water to remove surface dirt and grime. Next, spray a cleaning solution on the grout. You can mix your own by putting a 50-50 mix of vinegar and water into a spray bottle. Spray on the grout, let stand for five minutes and then scrub with a soft brush.
If it's light I spray with Tilex, let it sit for several hours, occasionally spraying to keep it wet. Scrub down with a stiff scrub brush and Soft Scrub. Rinse well. Once dried be sure to seal with tile/ grout sealer. You won't work do hard next time.
I use Kelli's technique with scrubbing bubbles. Usually it only takes a few minutes. Regardless, be sure to seal the grout when it's clean so you don't have this problem again.
Hi Shannon - 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. I've also included a great article about mold if it's gone that far. 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
Heres some other recommended cleaners
The Best Way to Clean Grout-EVER!!! | Hometalk
Painted Tile Grout Refresh with grout pen
Grout cleaning and grout removal and replace it
Here’s a Hometalk link for you to consider. Hope this helps