A fire clean up encompasses lots of things .
Odour removal, acid based soot removal, debris removal, is there asbestos present, the list is endless.
You need to establish the type of fire , what burned? this affects the choice of cleaning solution.
Start near the fire and work outwards , you need special claining solutions , flash and other household cleaners just wont do it properly.
What about floor voids, behind sockets and switches?
LOts to think about, a 3 bed semi fire job from say a chip pan fire , inc cleaning all clothing , soft furnishings, fixtures and fittings ,walls and woodwork , kitchen if not burned ,bathroom , fogging and ionizing would be around 5 grand , I would not charge hourlt , but would list the spec and add a price , hourly rates for clean up are up to about £25/ hour now.