There are a few things you can do to clean dirty seat belts in a car.

  1. Remove all of the fasteners from the belt loops. This will make it easier to remove the belt and make sure that all of the dirt and debris is removed.
  2. Use a vacuum cleaner to suck all of the dirt and debris out of the belt loops. Make sure to use plenty of suction, as it will take some time to clean everything.
  3. Rinse off any excess dirt and debris with water or soap. Be sure to dry everything off before putting it back in the car.