laminate floors with grain or groves that keeps filling with dirt when cleaned with mop and water
I have found that laminate floors need to be swept almost daily. Before cleaning them with a mop and water, be sure to sweep up any loose dirt, so it won't get stuck in the grooves.
I actually vacuum mine before mopping, with a lightweight stick vac.
Yes, unfortunately, laminate flooring with grooves is high maintenance.
As Cynthia said, vacuuming the floor first resolved any problems for me too