By this do you mean Tools or Chenmicals?
Tools
Scraper, rounded edges.
Small wire brush
Dip tray, better off having a heated dip tray as this is where you soak all the lose bits and bobs and bring back in to the client who will be amazed! You chemical goes in the dip tray.
A torch to see inside the oven.
Some extra long gloves and an apron or overalls
A dust sheet to place in front of the oven.
Standard screw drivers, replacement parts.
Caustic or non caustic chemicals for cleaning.
Wire wool.
Brushes and spray bottles.
small drill - you can purchase a drill bit that has a scourer on the end!
The list is endless
Dave