Have you tried the Muc-off yet?

Another vote for Wonder Wheels here, but not on Split Rims or unlaquered alloy.

If after leaving it to sit for 4 or 5 minutes (without letting it dry) it hasn't removed everything, then a clay bar is the way to go.

Another vote for Muc-off. It is great, also for those who have painted calipers spray on, hose of, nice a clean.

I had some wonder wheels.... It didn't shift the last little black bits and I would say was no more effective than the autoglym stuff :(

Think you could try the clay bar, although it could be that the metallic particles have burned their way into the paint on the alloys :(

Did you agitate it using the bristle brush? Stubborn areas may need repeated applications. I did the insides of some very bad Audi wheels today and got them looking like new. Perseverence is the key.

Yes i agitated it many times. It is ok, but it doesn't get rid of everything. The brush with it is IMHO too soft actually.