Ovenu have done a fantastic job, it's spotless (2 of them took 2.5 hours!).
How do I clean it and how often? It's supposedly self cleaning, which as we all know is a giant con, but it means I can't use strong, caustic stuff as the man said it would eventually eat away the inside of the oven.
Brillo pad and hot soapy water once a month?! 
Tell me what you do.