Hi James
I was in the same boat as you last week as i bought the Ark Grip off octet, I used the polishing attachments to clean up the tail pipes and rear boxes (as they are visual from the rear ), the inside of the tailpipes were black with soot etc, they now look chrome ! but I needed to polish with drill, I could not of acheived the result by hand ( I tried)
The rest I cleaned up using some bilberry wheel cleaner (diluted) as there was road tar on the pipes, I then polished with megs "all metal polish" , this offers " highest shine possible, anti-corrosive agents fight against eviromental attack and degradation"
Hth
Paul