If glasses come out sandy or the tub smells like a leftover, the cylindrical filter in the floor of the tub is usually packed. It is designed to come out by hand. It is also designed to go back in a specific orientation. A filter that sits crooked lets grit into the pump.
Wait until the dishwasher is off and cool. If standing water is above the filter, bail some out or you will flood the kitchen when you lift the mesh.
Where the gunk actually lives
Most Whirlpool tubs use a fine mesh cylinder plus a coarse screen. Food wraps the mesh; glass and seeds sit in the sump below. Rinse the mesh under the tap from the outside so debris does not embed deeper. A soft brush is enough. Skip steel wool.
Putting it back so the pump stays protected
The filter usually twists to lock. If it spins freely after you think you seated it, it is not locked. Run a short cycle and listen: a rattle from the floor of the tub can mean the assembly is loose.
What this will not fix
A crushed drain hose, a disposer knockout that was never removed, or a dead drain pump will still leave a puddle. Cleaning the filter is maintenance, not a pump replacement. If water returns immediately with a clean filter, stop running loads.
