swish and spit
n.— «It requires transoceanic vessels to dump ballast water at least 200 miles from shore. Those carrying no ballast must rinse their tanks with salt water, a process known as “swish and spit,” to kill organisms lurking in residual puddles or mud.» —“EPA permit requires ballast water exchange” in Traverse City Battle Creek Enquirer (Michigan) Dec. 19, 2008. (source: Double-Tongued Dictionary)