Follow the exact manufacturer's instructions promptly. Salt left in unintended areas can be a concern, and the recommended clearing sequence is model specific.
Understanding this situation
Do not confuse loose grains with an instruction to add more detergent or another chemical. The reservoir cap also needs to be refitted correctly before any permitted programme.
A useful next step
Use the documented procedure for removing or rinsing spillage and avoid leaving it unattended in the cabinet. If a wrong product was poured into the reservoir, that is a different situation requiring advice. Do not treat a normal spillage instruction as permission to flush anything through.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.