My KEF KHT2005 'egg' speakers in black have become very sticky. I have just moved house, packed them in the original boxing but on unpacking they now have chunks of polystyrene stuck to them. Is there any way they can be cleaned, or is there anything that KEF can do? I think they're about 7 years old. Thanks.

Audio Players & Recorders - KEF Audio - KHT 2005.2 System