Visit the website of Bilt Hamber, they manufacture a new type of wheel cleaner which will not damage the finish, it is not cheap, there are other copies of this on the market slightly cheaper so by all means use your own judgment.

Though even with this potion, its still best IMO to only use chemicals when the dirt gets so ingrained that washing with ordinary washnwax during the weekly car wash won't shift it.

I would also suggest using a high quality wax polish designed for wheels on them, i use Poorboys, once you get them spotless and dried off, diamond cut and laquer may be pretty but its the least resistant finish i know of against salt attack through the minutes pin hole.