Hi ya Jon
it's a little bit more technical than what's being said here, the odour removal is extremely difficult and it depends on several things including the type of fire to what extent the property has been exposed to the smoke and the amount of time the smoke has been left in the property, surfaces such as chrome taps, upvc windows, lino flooring can become permanently damaged if soot has laid on them for more than 48 hours as soot can produce an acid, equipment such as hepa air scrubbers, and thermal fogger might be required, cleaning materials such as air neutralisers, bad odour blocks may be required.
Smoke damage is a specialist service which for insurance point of view they would require someone that has been trained possibly as a smoke damage technician.
We've all got to start somewhere but watch you don't take on too much as smoke damage is very labour intensive, my best advice to you mate is to contact the national flood school who have got all the necessary equipment and materials and run a fantastic recognised certificated course which is very informative.
By all means ask for Gemma, Chris, Stuart or Lawrence they are very helpful people
Best of luck

Richie