yes, the Canaanite enemies of deborah and barak were destroyed ("swept away") at brook ki-shon many years ago (Judges 5:20-21). It would be a place of remembrance for the people of this very great and significant Israelite victory over Jabin/the Canaanites wrought by God at the hand of Barak and Deborah - a great judge. The Baal prophets were not a sacrifice ... they were slain because God commanded it in the Law, being enemies of Israel and being false prophets on top of it. It is to be seen that as the account in Judges records: “all the host of Sisera fell upon the edge of the sword and there was not a man left” (Judges 4:16-17), so of the Baal prophets it is written: "let not one of them escape" (1 Kings 18:40), and Ahab reported to Jezebel that Elijah "had slain all the prophets with the sword" (1 Kings 19:1). It is to be seen that the old covenant scriptures (and the New for that matter) are replete with tradition and signs and specific references to events in the grand history of this people, as everything that was encountered can be attributed to the will of God. It made perfect sense and was a very symbolic act borne of his love for and fear of God (which Elijah we suppose hoped would also be in the hearts of the people) for Elijah to take the Baalist enemies to the Brook Ki-shon that they might also be "swept away", as had been the Canaanites those many years before. By this symbolic act, Elijah would (we may reason) hope that the people's fear of God would be increased even more than it perhaps was after they had witnessed God's consuming fire on the altar at Mount Carmel. God had orchestrated all of the events at Mount Carmel for one reason - that His people would heed his prophet's words and turn their hearts back to God. Elijah "pulled out all the stops" using the many and diverse provisions God made available to him in this glorious account.