"flushing" as i undertand it, is to make a withdrawal non-reversible and to bypass the period of time that the money sits in the account (during the reversible period.) So if a withdrawal usually can be "reversed" for two days, flushing it will bypass those two days and start the payment process immediately without any option to reverse it.
And the only satisfactory answer, IMHO, should be: "Of course, give me a second and i will flush your withdrawal immediately so we can start your withdrawal process. Is there anything else i can help you with?"
