There are a few things you can do to clean vomit from a car seat belt.

  1. Pour a pot of boiling water onto the vomit and pour it all over the area where the vomit was located. Let the water cool for a few minutes, then use a plunger to suction onto the vomit and pull it out.
  2. Use a vacuum cleaner to suck out all of the vomit from the car seat belt. Be sure to empty the vacuum cleaner before putting everything back in its original place.