If a barrel of well water falls into the Mediterranean and a person comes to immerse where that water fell into the sea, that dunking is not effective - on the assumption that the water doesn't blend/disperse quickly. With some attention to other mixtures - such as wine in the Mediterranean, and more. Also, a new mishnah - back to the conspiring witnesses, and the monetary cases where the witnesses get lashes for false testimony and also are dunned for paying the amount they were attempting to force their victim to pay. Plus, the contrast between conspiring witnesses and the fines levied against someone who slanders (motzi shem ra).