Can of Gunk (spray kind). Cover up all electrical plugs/ends with cling film and then just spray the Gunk everywhere. Let it work for a couple of minutes, it will fizzle on the really grimy bits and then just spray away. Get some back to black on the rubber hoses and other plastic bits and it will look good as new, with very little effort.
Good shout apart from the black to black, I can't stand that stuff tbh
AG Vinyl & Rubber Care is a nicer product to use, but then again it's personal preference.
Do they sell this 'gunk in halfords?
...Sad to say the CTR has now gone but I know I have done the right thing