You are not going to get your wheels perfect. The brake dust has already damaged or embedded itself in the clear coat. At this point all you can do is make it look better but it will never be perfect. This is the difference between a novice and a detailer. A detailer knows when to stop before he does damage and makes it look the best he can. A novice keeps striving for perfection and then goes ooops I went too far now what? Best you can do is make it look better. There are various things you can try
Try a polish to "flatten" the brake dust so it is not as noticeable. You may not get all of it and you have to watch so that you don't go through the clear coat. Put a good coat of wax and or sealer on it and you're done.
The other option is to try a very fine sandpaper like 1500-2000 to lightly level out the brake dust then a polish to restore the shine. Again just a little or you'll go through the clear coat. After a good coat of wax or sealer.
Again the goal is to hide the damage not make it perfect. Not everything can be brought back to perfection. Damage is after all damage, sometimes you can just minimize it or hide it so it is not as noticeable.