The doors can be removed and fully dismantled. They are triple glazed and the two removable pieces from each door are put in the (over night) oven cleaning bag along with all the racks and rack supports and a bottle of cleaning solution. The body of the door is cleaned with an oven cleaning paste.
The oven and grill are continually sprayed with oven stuff then left over night.
I attack the racks the next morning with metal scourers and a drill attachment for the awkward bits. Same with the oven and grill body. The roof of the oven is the toughest bit.
The glass lamp covers are also cleaned. An area of about 2m around the sink and the oven itself also have to be cleaned afterwards.
All in all about 6 hours work to dismantle, soak, clean and re-assemble. I wreck two pairs of rubber gloves in the process, usually down to handling the drill.
How much do you charge her?