i've been doing oven cleaning for some time now as an additional service only when people move house. it's been fairly easy as we're left to do the whole house and the oven so can use tanks inside the house, take a little longer, and haven't yet been expected to change a bulb, seal etc.
i'm looking to make this a proper service now and feel a bit overwhelmed at how much stuff i will need on top of the basics. scratchy balls, glass scraper etc these are obvious, but what about things like the door seals, they aren't all alike, but where do people get these from and how many types do they carry? what are all the types of different bulbs used in ovens? what other random supplies do people have that you wouldn't expect to need but can come in handy?