I don't see the need to add anything to the engine oil to "clean things up" prior to an oil change. If you are using quality oil, changing it regularly, and allowing the engine to come up to full operating temperature before parking the truck, you won't have any sludge buildup and shouldn't have anything to "clean out". Not to mention the fact that if you are successful at breaking the stuff loose all you will accomplish is clogging your oil pump pickup tube in the bottom of the oil pan. Just my 0. 02 worth.