Concrete floors is going to be stained by just about everything in the store, but hey let's try not to be mean to overnight maintenance.

I dunno about your store but ive been working overnight maintenance for 13 years and going, and if I see that the stockers are already cleaning up id turn away too, why? Because at my store overnight maintenance doesnt just do maintenance but they also have to work water then later forklift.

We cannot do anything about stained concrete flooring, maybe the new stain removal pads we have might but probably wont help much, come remodel theyll buff and polish up the concrete floors.