Going back to your original post, I'd also have the inlet manifold removed and cleaned and the inlet ports walnut blasted. No amount of fuel additive cleaners or inlet aerosol sprays are going to remove carbon/sludge.
I had the IM and ports done on my 30D a couple of weeks ago, 82K miles, and the build-up was getting quite heavy.
Here's a link to my post and pics :
https://f30.bimmerpost.com/forums/sh....php?t=1560517
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Current : F31 330sD, remapped, Ohlins Road & Track, Millway camber plates, Quaife LSD, Stoptech brakes + Pagid RSL1 pads all round, Weichers front strut brace, Eibach front & rear anti-roll bars, Michelin MP4S.