Grit is an observable deposit, not a diagnosis. Its distribution and the recent load can help distinguish trapped food or other material from a finish change.
Understanding this situation
Check the model's routine filter-care guidance and whether items were nested or overloaded. Do not assume every grain is salt, and do not taste residue to identify it.
A useful next step
Use only permitted owner cleaning with the machine safe and handle sharp debris cautiously. Record whether grit affects all racks or sheltered surfaces. Persistent residue after appropriate loading and care should be assessed rather than treated with random extra chemicals.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.