How does GT85 differ from WD40?
I can’t find any clue on their websites.
Confirm Magic Sponges work for me …and the car.
If you buy online get the biggest ones you can find as the small ones disintegrate in a flash.
Cleans shoes,kitchen sinks , even upholstery…all wit the usual disclaimer!
Oh and no you are not alone in wanting to keep your bottom clean!
In Karting on of the most popular cleaners is Elbow Grease. Get it from a pound shop and put it in a Werth brake cleaner dispenser, then pump up the bottle and spray. Use a paint brush to get it in corners and hard to reach places and rinse off. It’s fine to use on plastics, metals and even fabrics.
magic Sponges. With whitespirit mixed with car shampoo is good . 
autosol takes time . 
You are an Exiger now so dont be worried about excessive cleaning …we all do it . its all partof Pesky’s “Exigeness
Syndrome”…there is no cure.!! 
GT85 for me,use it to clean and spray a coat on the surface after. In tests it gave longer lasting protection than WD40… apparently… and its a bit cheaper.
So do we think magic sponges plus wd40/gt85 will be able to lessen the impact of some fine scratches?
As they say on the tin…" try a test in a less obvious place first." 
You dont want to scratch the anodizing …it will only make it worse 
Here speaks the voice of experience 
As said above - it will take any dirt out of the scratch but don’t rub as if you are trying to get rid of the scratch - you will only make it worse.