Only follow a flushing procedure if the exact model instructions explicitly provide one. A drain opening is not a general disposal point for leftover detergent or disinfectant.
What the observation tells you
Liquids may travel to concealed areas, and an excessive quantity can overflow or reach components not designed for that treatment. Different products also have different material compatibility. The presence of a visible hole does not establish that a kettle of water or a chemical mixture is appropriate.
A useful next step
Use the prescribed accessible cleaning technique and remove spills with a suitable cloth. If drainage remains poor, describe the recurring water pattern instead of increasing the quantity or strength of liquid added.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.