The square strainer basket for floor sinks serves a dual purpose: first, it prevents sediment from entering the drain line... second, it allows for easy cleanup and disposal of the waste material that has been collected. At our supply house, we sell these to both plumbing contractors who are involved in drain cleaning, and to restaurants who are trying to avoid clogged drains that need to be cleaned!
I just started putting these in some of my restaurant accounts to show them what exactly is going down their drains & why they're having drainage issues, smells, back-ups, etc. The baskets catch most of the food debris that comes from the sinks & is easily accessible for the staff to see & remove for clean-up.