How do you clean really dirty tile grout?

Cleaning really dirty tile grout can be a challenging task, especially if the tile grout is in high-traffic areas, or if the building is open for public use. Here are a few methods that you can use to clean really dirty tile grout:

1. Use a commercial-grade grout cleaner: There are a variety of commercial-grade grout cleaners available that can be used to effectively remove dirt, stains, and mildew from tile grout. These cleaners often contain powerful cleaning agents that can break down dirt and stains.
2. Use a high-pressure steam cleaner: High-pressure steam cleaners can be used to effectively remove dirt, stains, and mildew from tile grout. The high-pressure steam can loosen dirt and stains, making it easier to clean. This method is efficient and fast, it's also environmentally friendly as it doesn't require the use of harsh chemicals.
3. Use a rotary or oscillating machine: This type of machine is equipped with a rotating brush or pad that can be used to scrub away dirt and stains from tile grout. This method is effective but may take longer than using a high-pressure steam cleaner.