Tip for anyone who has a grubby keyboard with a build up of exfoliant, dust and grime. I used a product that I have been using on my Mac keyboard for a few years called Super Clean by Rovtop. It's a sort of green slime that you rub over the dirt and it just absorbs the dirt and dust and leaves the silicon in new condition. It also rolls over the waves really easily because it's a sort of blob. I've used it a few times now and it does a great job and doesn't appear to harm the silicon.