5 hours to clean it. You buy a kit complete with a large bag, fluid and gloves. Strip the cooker and remove the doors. The doors strip down so you can access the triple glazing. You put all the components in a bag and empty half the fluid into the bag and let it all soak. The other half you spread around the inside of the oven and grill.
You then set about cleaning what's left of the doors and attack the inside of the oven once the fluid has soaked in.
You can attack what is in the bag after a couple of hours and it is a miserable time scrubbing with a scourer, working into all those tiny runs of steel. Takes ages to get all the crud off. I even dismantled both lamps and cleaned the lenses and bulbs.
I have to say, the Bosch kit dismantles nicely and is put together well.
If yer gonna do a job......