restaurants have laundry service for kitchen pants, jackets, aprons, right along with all the towels, napkins, and tablecloths. They aren't the employees own clothes they got from walmart, they are provided by the laundry service like the towels.
I have worked at sit down dining and fast food, and neither places did my laundry for me. Aprons, sure, but not the rest of the clothes. The clothes which I had to buy in the first place.