how do i clean rusty cast iron properly?

guessing the shirt bit is a typo? for a rusty pan: scrub the rust off with steel wool and a little water until you see bare grey metal. it'll look worse before it looks better. dry it straight away on the hob over low heat, then rub a very thin coat of oil all over, inside and out, and wipe off as much as you can so it looks almost dry. bake upside down in a hot oven for an hour. thin coats are the whole trick - thick ones go sticky.