BlueRanger,
The sponge picks up quite a bit of dirt in the wheel wells. I didn't take off the wheels, so I was only cleaning what I could reach in front of and behind the wheel. It did take some elbow grease, but no more than 5 minutes per wheel well. They were dirty, but not caked on. It was not a pure autopian effort, but it did return the wells to a black color so the wells didn't stand out. The process I'm recommending is just a quick attempt to improve the overall look of the wells, and not an all out assault on grime. That's where a brush and an all purpose cleaner would have come in handy. There are much better methods out there if you want a new car look. It was getting late and it was the best effort I had at the time.
On the abrasiveness scale, #82 and #9 are about the same. I haven't tried #82 personally, but did a search on "abrasiveness scale" and read a few posts to find a list that was previously passed around.
The DACP I initially used took care of most of the swirls, and I was hoping for that last little bit of perfection when I used #9. The swirls (spiderwebbing) were completely gone after #9, and the AIO only revealed scratches that were too deep for a PC and DACP to fully eliminate. There were a couple places where I probably could have used a rotary, but that's outta my league for now.
I've used #9 to eliminate spiderwebbing and light swirls, but it does fill some of the deeper ones. That's when I break out something stronger, like DACP. If I'd only used #9 without the DACP I think the AIO would've revealed a lot of surface marring.
Sorry for the rambling, but wanted to give you the benefit of what my experience was.