Ok I finally listened to the GM song. There is medium delay, very digital sounding verb, and almost certainly a chorus dialed in fairly subtly. Well the chorus is not exaclt subtle on this is it?
I think the DimD would be an excellent starting point to get this (along with delay/verb) but you may need to filter the result with an eq (pre or post DimD, i dunno), and obviously you would want to use the DimD on a bus.
Man in the Mirror, however is a little different. I hear a lot less chorusy effect on the vocal where it is NOT doubled. And it is doubled frequently. There is also delay on this one, but much shorter, and there is a slightly warmer verb, but still something out of the 80s toolbox.
My favorite part of that song is the choir recording. So lively and all-around-you sounding. I seem to remember reading that Bruce Swedien used a blumlien setup on the choir with the choir in a circle around the two mics. Seems to have worked!
And yes... a LOT of the sound of the George Michael vocal has to do with the performance and mic/pre... But if you were to sing a little breathily and work to get a sweet lift on the highs without boosting too much 5k along with a very subtle chorus, and less subtle delay and verb I bet you can get in the ballpark.
But knowing your baritone voice... if you want to actually want to sing LIKE GM you are gonna need to get a clothespin and place it down on your... well... I don't really think you want to sound like HIM, just produce a similar effect on the vox?
cAPS