I supposed that thelinks of london jewellery black marks are on the white rubber area of the shoes. If that is the affected area I recommend you to use a little stone (you can find it at the yard of your home), this method links london consist on scrub with few wather the rubber with the piece of rock. You will notice how it works!
Here you can see 100% Authentic Eded hardy Hardy Items that you can wear with this awesome shoes once you have cleaned it. Check them Outedhardy .The website is I hope this help you!