No pre-cleaning or prep, other than disassembling the pieces as far as you can. For an intake, I'd give it at least a day in the soak, charger on the whole time. Do this outside! Dont smoke near it. You will have to brush or scrub afterwards. The process separates the attached rust first, so you end up with a cocoon around the part. Your sacrificial pieces can be wiped off, but you'll be shocked how eroded they are. Don't use stainless as your sacrificial pieces (makes poisonous gas). Good luck
