I've had second thoughts on this: a 220 grit stone is probably a bit aggressive and might unnecessarily widen the bevel. Just start with a few passes on a 1000 grit hone, that should be enough to discover whether you have clean metal at edge and therefore the ability to set the bevel without corrosion pits ruining it. If you're inexperienced at honing you may wish to then do a clean up of the blade to the point where you're satisfied with the finish and then send it on to an expert to bring the edge up to the shave ready level. There are a few people in Australia who offer honing services, including Oz (Onimaru55) who is very highly regarded.