1.Arrange Onion Slices Evenly Over The Bottom Of The Slow Cooker, And Then Place The Roast On Top Of The Onion. In A Bowl, Mix Together Water, Sugar, Vinegar, Soy Sauce, Ketchup, Black Pepper, Salt, Garlic Powder, And Hot Sauce; Pour Over Roast. 2.Cover, And Cook On Low For 6 To 8 Hours, Or On High For 3 To 4 Hours.