Can I switch a flooded appliance back on once its outside feels dry?

Do not use switching it on as a safety test. CDC says electrical equipment and appliances must be completely dry before returning to service and calls for a qualified electrician's check when there is doubt. Ask a qualified appliance technician or electrician to assess the exposed components and explain whether cleaning, repair or replacement is appropriate. Photograph identifying details when safe. A working display or dry exterior is not a substitute for that assessment.