LulaBell,
I'm not sure if I can be much of a help cos I had similar problem - but with my beige
caviar. So I'm not sure if it would work the same on patent. But I just share my experience anyway.
6 months ago, I brought my poor bag to Chanel after baby wipes didn't seem to help at all this time (it happened before, a colour transfer from
another jacket and the baby wipes did wonder - but this time no).
Disappointingly, the Chanel SA told me there's nothing they could do to remove those black colour transfer from my jacket (can't believe they couldn't even provide this service eventhough my bag is less than 1 year old).
There's only one Chanel store here so this was what I did out of desperation (I'm not being paranoid but mine was really BAD! It covered almost the whole back pocket of the classic flap, plus strap & every single corners back & the front).
I took the shot and purchased apple
conditioner (the shipping is high than the item itself!) after reading that there's a tpf member here who used it on her black lambskin. And she emphasised on the apple
conditioner not the apple guard.
When I applied the conditioner on my bag, at first it didn't seems to get rid of the stain. But it sure improved the look of the stain & condition my bag. So I re-do the same steps few minutes later.. -still the same result - and I leave it in the open overnight (not in the dustbag).
The next day, I'm surprised all the black stains were gone!!
To be honest, I was just looking at my bag few days ago and I still cannot believe it I couldn't see any stain at all.