Putting anything inside an intake passage that might slough off later and end up in the engine probably isn't a good idea. Once a part is de-rusted, use a garden sprayer to fog it down with Diesel fuel, and then seal it inside a plastic bag if you're not going to assemble the engine right away. One of my students used to preserve entire engines for years by disassembling them, putting the pieces into a ring-top 55 gallon drum, and filling it with Diesel fuel or agricultural hydraulic fluid. If the humidity can't get to the part it can't rust.
Jerry
