Avoid repeat demonstrations
An existing recording may help; there is no need to flush repeatedly to create one. Mention anything entering the fixture immediately before the sound changed.
Keep connected symptoms
Slow clearing, prolonged running and leakage matter alongside noise. A professional assessment can distinguish an obstruction enquiry from a wider appliance problem without opening the unit yourself.
A useful distinction
A sharp new noise after a known foreign item differs from a gradually lengthening run. Neither description confirms an internal part, but the distinction can change the initial assessment and proposed work.